The force applies an acceleration in the reverse direction of
29 N = (0.145 kg) a → a = 200 m/s²
and in order to hit the ball back with speed 40.0 m/s, this acceleration is applied over time t such that
200 m/s² = (40.0 m/s - (-40.0 m/s)) / t → t = (80.0 m/s) / (200 m/s²) = 0.4 s
How much POWER is used in 30 seconds when you complete 150 Joules of work?
Answer:
Power of 5 watts is used
Explanation:
Mechanical Work and Power
Mechanical work is the amount of energy transferred by a force.
Being F the force vector and s the displacement vector, the work is calculated as:
[tex]W=\vec F\cdot \vec s[/tex]
If both the force and displacement are parallel, then we can use the equivalent scalar formula:
W=F.s
Power is the amount of energy converted per unit of time. The SI unit of power is the watt, equal to one joule per second.
The power can be calculated as:
[tex]\displaystyle P=\frac {W}{t}[/tex]
Where W is the work and t is the time.
It's required to calculate the power used in t=30 seconds when W=150 Joules of work are completed. Substitute in the formula:
[tex]\displaystyle P=\frac {150}{30}[/tex]
P = 5 Watt
Power of 5 watts is used
A skater embeds a firecracker in a large snowball and pushes it across a frozen pond at 7.6 m/s. The firecracker explodes, breaking the snowball into two equal-mass chunks. One chunk moves off at 9.3 m/s at 19° to the original direction of motion. Discover the speed and direction of the second chunk.
Answer:
[tex]v_2 = 6.406 / cos25.29[/tex]
Explanation:
From the question we are told that
Speed of snow ball 7.6m/s
Speed of chunk 9.3m/s at [tex]19 \textdegree[/tex]
Generally the equation for the conservation of momentum is mathematically given as
Let the snow ball be b
and the chunk b/2
According to conservation of momentum we have
[tex]b_u = (b /2) v_1 cos\theta_1 + (b / 2) v_2cos\theta_2[/tex]
[tex]v_2 cos\theta_2 = 2 * 7.6 -9.3 * cos_19[/tex]
[tex]v_2 cos\theta_2 = 15.2 -8.793 = 6.406[/tex]
Therefore
[tex](b/2)v_1 sin\theta_1 = (b/2) v_2sin\theta_2[/tex]
[tex]v_2 sin\theta_2 = 9.3 * sin_19[/tex]
[tex]v_2 sin\theta_2 = 3.027[/tex]
Mathematically From above equations
[tex]tan\theta_2 = 0.4726[/tex]
[tex]\theta_2 = 25.29 \textdegree[/tex]
Therefore the speed and direction of second chunk
[tex]v_2 = 6.406 / cos25.29[/tex]
[tex]v2 = 7.0855m/s[/tex]
A helicopter is flying 8 kilometers above the ground. It has a gravitational potential energy of 376 Joules. What would the mass be?
Answer:
0.0048kg
Explanation:
Given parameters:
Height of flight = 8km = 8000m
Gravitational potential energy = 376J
Unknown:
Mass = ?
Solution:
To solve this problem;
Gravitational potential energy = mgh
m is the mass of the body
g is the acceleration due to gravity
h is the height of the helicopter
Insert the parameters and solve;
376 = m x 9.8 x 8000
376 = 78400m
m = 0.0048kg
What is the force of gravitational attraction between an object with a mass of 100 kg and another object that has a mass of 300 kg and are at a distance of 2m apart
Answer:
5 x 10⁻⁷N
Explanation:
Given parameters:
Mass of object 1 = 100kg
Mass of object 2 = 300kg
Distance = 2m
Unknown:
Force of gravitational attraction between the objects = ?
Solution:
Newton's law of universal gravitation states that the gravitational force between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
From Newton's law of universal gravitation we derive an expression:
Fg = [tex]\frac{Gm_{1} m_{2} }{r^{2} }[/tex]
G is the universal gravitation constant = 6.67 x 10⁻¹¹
m is the mass
r is the distance between the bodies
Now insert the parameters and solve;
Fg = 6.67 x 10⁻¹¹ x [tex]\frac{100 x 300}{2^{2} }[/tex] = 5 x 10⁻⁷N
A merry-go-round initially at rest at an amusement park begins to rotate at time t=0. The angle through which it rotates is described by θ(t)=πk(t+ke−t/k), where k is a positive constant, t is in seconds, and θ is in radians. The angular velocity of the merry-go-round at t=T is
Answer:
Angular velocity of merry-go-round is πk - 1 at t= T
Explanation:
From the question it is given that
[tex]\theta(t) = \pi k(t+k_e-\frac{t}{k} )[/tex] ..........................(1)
since mathematically, angular velocity is defined as
[tex]\omega(t) = \frac{d\theta(t)}{dt}[/tex] ........................(2)
on substituing the value of θ(t) from equation 1 in equation (2) we get
[tex]\omega(t) = \frac{d\theta(t)}{dt}[/tex] = [tex]\frac{d\pi k (t + k_e - \frac{t}{k} )}{dt}[/tex] ............................(3)
on differentiating equation (3) with respect to time we get
ω(t) = πk(1 -[tex]\frac{1}{k}[/tex]) = πk - 1 angular velocity of merry-go-round
Therefore, angular velocity of merry-go-round is πk - 1 at t= T
The angular velocity of the merry-go-round at t=T is πk - 1. The pace at which angular displacement changes is defined as angular velocity.
What is angular velocity?The rate of change of angular displacement is defined as angular velocity.
It is stated as follows:
ω = θ t
The equation for the angular displacement is given as;
[tex]\theta (t) = \pi k (t+k_e-\frac{t}{k} )[/tex]
The angular velocity is found by the differentiation of the angular displacement.
[tex]\rm \omega(t) = \frac{d(\theta)}{dt} \\\\ \rm \omega(t) = \frac{d (\pi k (t+k_e-\frac{t}{k} )}{dt} \\\\ \rm \omega(t) = \pi k-1[/tex]
Hence the angular velocity of the merry-go-round at t=T is πk - 1.
To learn more about the angular speed refer to the link;
https://brainly.com/question/9684874
A 620 kg moose is standing in the middle of a train track. A 10,000 kg train moving at 10 m/s is unable to stop and the moose ends up riding the cowcatcher down the track. What type of interaction is this, and what is the new combined velocity
Answer:
This is an example of Inelastic colission
Explanation:
Step one:
given:
mass of moose m1 = 620 kg
mass of train m2= 10,000kg
Initial velocity of moose u1= 0 m/s
Initial velocity of train v1 = 10m/s
combined velocity of the system is given as v
Applying the conservation of momentum equation we have
m1u1+ m2u1= (m1+m2)V
substitutting we have
620*0+10000*10= (620+10000)V
100000= 10620V
divide both sides by 10620
V = 100000/10620
V=9.41m/s
The velocity of the moose after impact is 9.41m/s
When did the object have the highest average
speed? *
5 points
Time (s)
30
Distance (m)
90
240
60
120
580
180
1080
O Between 0 and 30 seconds
Between 30 and 60 seconds
Between 60 and 120 seconds
Between 120 and 180 seconds
Answer:
Between 120 and 180 seconds
A mechanism which uses mechanical energy to produce electrical energy is known as an) -
O electric motor
O transformer
O electromagnet
O electrical generator
I NEED HELP WITH THE LAST QUESTION I’L MARK U AS BRANLIEST
The question is: how would you connect the cells?
Answer:
gap junctions,tight junctions,and desmosomes
I really need help. I want a detailed solution
Answer:
v_{f} = -0.693 m / s
Explanation:
The acceleration of the runner can be obtained from Newton's second law
F = m a
a = F / m
the bold are vectors, therefore the acceleration throughout the journey varies as the force has variations.
For the part of finding the velocity of the body we can use the relationship between the momentum and the variation of the momentum
I = Δp
∫ F Δt = m [tex]v_{f}[/tex] - m v₀
int F dt = m (v_{f}-v₀)
1) To find the change in velocity we must find the area under the curve of the graph, this can be done analytically if we know the functional of the curve or approximate it by intervals
a) between 0 <t <0.20 s
v) between 0.20 <t <0.30 s
a reasonable curve shape can be a Gaussian.
2) If we do not have the form of the cure, we can perform a graphical integration to find the area under the curve, we can do this by dividing the curve into small rectangles, finding the area of each one and adding them.
3) Another even more approximate way is to create an average force in each interval and find the area of this force, the average force is the average value of the force in the interval, let's use this method in the exercise
a) first interval 0 <t <0.20 Average force [tex]F_{mean}[/tex] = 300 N
area = F_{mean} Δt
area = I = 300 0.20
I = 60 N s
the speed change is
I = m Δv
Δv = I / m
Δv = 60/65
Δv = 0.923 m / s
If we assume that the runner starts from rest, his final velocity is v = 0.923 m / s in the direction of the force.
b) second interval 0.2 <t <0.30s average force F_mean = 150 N
area = I = 150 (0.30 - 0.20)
I = 15 N s
the speed change is
Δv = 15/65
Δv = 0.23 m / s
Note that in this case the initial speed is not zero and since the two impulses are in the opposite direction the speed decreases
[tex]v_{f}[/tex]= -0.923 + 0.23
v_{f} = -0.693 m / s
A 0.290 kg block on a vertical spring with a spring constant of 5.00 ✕ 103 N/m is pushed downward, compressing the spring 0.110 m. When released, the block leaves the spring and travels upward vertically. How high does it rise above the point of release?
___m
Answer:
The height at point of release is 10.20 m
Explanation:
Given:
Spring constant : K= 5 x 10 to the 3rd power n/m
compression x = 0.10 m
Mass of block m= 0.250 kg
Here spring potential energy converted into potential energy,
mgh = 1/2 kx to the 2 power
For finding at what height it rise,
0.250 x 9.8 x h = 1/2 x 5 x 10 to the 3 power x (0.10)to the 2 power) - ( g= 9.8 m/8 to the 2 power
h= 10.20
Therefore, the height at point of release is 10.20 m
When you look at a star, where in space are you looking?
A. Into the galaxies
B. In the Milky Way Galaxy beyond Pluto
C. Towards the sun
D. At the failed star known as Jupiter
Answer:
A
Explanation:
into the galaxies of the
Answer:A
Explanation:I’m taking the test rn
two pictures show friends playing with a string telephone. in which picture can they hear each other
Answer:
In picture one because string telephones are best heard when there is more tension on the string
Explanation:
a)
F E
60. The temperature of source and sink of cannot engine are 400K
and 300K respectively. What is its efficiency?
h) 75%
c) 33.3% d) 25%
Answer: 25%
Explanation:
From the question, we are informed that the temperature of source and sink of cannot engine are 400K
and 300K respectively.
The efficiency will be calculated as:
= 1 - t/T
= 1 - 300/400
= 1 - 3/4
= 1/4
= 25%
A girl and a boy pull in opposite directions on strings attached to each end of a spring balance. Each child exerts a force of 20N. What will the reading on the spring balance be? 20 N 10 N 40 N 0 N
Answer:
yo they deleted my answer. The answer is 0N
Explanation:
so when two forces pull on an object from opposite sides with the same force (in this case its 20N), then the object is in equilibrium at 0N.
So its clear that there is one person on the the opposite side.
SOOO generally: (left or down) would be considered negative in an equation. And the other person (right or up) would be considered positive. So if both forces are the same numbers on opposite sides then the answer is 0 (if you add both of them).
0 is the number of equilibrium.
OK, so the equation would be -20N + 20N and then badda bing badda boom viola, the answer: 0N
thanks for coming to my TED talk. I hope they don't delete this answer.
You throw a ball into the air. Which two forces cause the ball to gradually stop moving upward and then fall back to Earth?
A.
Balanced forces
B.
Friction
C.
Normal force
D.
Gravitational force
will mark brainliest
Answer: Gravitational Forces
Explanation:
__________ energy always moves from a warmer object to a cooler object.
A) electromagnetic
B) nuclear
C) thermal
Which property of a mineral is shown in the picture?
Cleavage
Color
Luster
Streak color
Answer:
Looks like streak color.
Explanation:
The rock has potential energy due to the gravitational potential with the Earth. As the rock is falling, this gravitational energy becomes less. What happens to that energy? Question 11 options: The energy disappears. The energy is transformed into kinetic energy. The energy is absorbed by the ground and the air The energy is transformed into chemical potential energy.
Answer:
Explanation:
while it is still falling it is turned into kinetic energy. While on the floor it turns onto potential energy. Remember energy cannot be created or the destroyed so the other ones are automatically out.
How much heat is needed to rise the temperature by 10 oc of mass 5kg if substance of specific heat capacity 300j/kg of What is thermal of a substance
Answer: 15000 J
Explanation:
Given ;
Temperature change, dθ = 10
Mass of substance, m = 5 kg
Specific heat capacity, C = 300 j/kg°C
Quantity of heat, Q required is obtained using the relation ;
Q = mCdθ
Q = 5kg * 300 j/kg°C * 10°C
Q = 5 * 300 J * 10
Q = 15000 J
Which occupies more volume: 3m^3, or 100 ft^3?
Answer:
3 m³ will occupy more volume.
Explanation:
We need to tell which occupies more volume : 3m³ or 100 ft³.
To compare, we first make the units same.
We know that,
1 m = 3.28 feet
1 m³ = 35.31 foot³
3 m³ = 105.94 foot³
Now, we can compare 105.94 foot³ and 100 ft³. It can be clear that 3 m³ will occupies more volume.
What is the resistance of five 10Ohm resistors in parellel?
Answer:
The equivalent resistance is 2 ohms.
Explanation:
let the first resistance = R₁ = 10 ohm
let the second resistance = R₂ = 10 ohm
let the third resistance = R₃ = 10 ohm
let the fourth resistance = R₄ = 10 ohm
let the fifth resistance = R₃ = 10 ohm
The equivalent resistance is calculated as;
[tex]\frac{1}{R_T} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \frac{1}{R_4} + \frac{1}{R_5} \\\\\frac{1}{R_T} = \frac{(R_2R_3R_4R_5)+(R_1R_3R_4R_5)+(R_1R_2R_4R_5) +(R_1R_2R_3R_5)+(R_1R_2R_3R_4)}{R_1R_2R_3R_4R_5} \\\\R_T = \frac{R_1R_2R_3R_4R_5}{(R_2R_3R_4R_5)+(R_1R_3R_4R_5)+(R_1R_2R_4R_5) +(R_1R_2R_3R_5)+(R_1R_2R_3R_4)} \\\\R_T = \frac{(10^5)}{(10^4)+(10^4)+(10^4)+(10^4)+(10^4)} \\\\R_T = \frac{10^5}{5(10^4)} \\\\R_T = \frac{10}{5} \\\\R_T = 2 \ ohms[/tex]
Therefore, the equivalent resistance is 2 ohms.
Given the information below, estimate the total distance travelled during these 6 seconds using a left endpoint approximation. time (sec) velocity (ft/sec) 0 30 1 54 2 56 3 34 4 8 5 2 6 22
Answer:
184 feets
Explanation:
Given the data:
time (sec) __ velocity (ft/sec)
0 __________30
1 __________ 54
2 __________56
3 __________34
4 __________ 8
5 __________ 2
6 __________22
Using left end approximation:
(0,1) ___ f(0) = 30
(1,2) ___ f(1) = 54
(2,3) ___f(2) = 56
(3,4) ___f(3) = 34
(4,5) ___f(4) = 8
(5,6) __ f(5) = 2
Hence, the Total distance traveled during the 6 second interval is:
Change ; dT = 1
1 * (30 + 54 + 56 + 34 + 8 + 2) = 184
A system consists of two particles. Particle 1 with mass 2.0 k g 2.0kg is located at ( 2.0 m , 6.0 m ) (2.0m,6.0m) and has a velocity of ( 3.1 m / s , 2.6 m / s ) (3.1m/s,2.6m/s). Particle 2 with mass 4.5 k g 4.5kg is located at ( 4.0 m , 1.0 m ) (4.0m,1.0m) and has a velocity of ( 1.1 m / s , 0.6 m / s ) (1.1m/s,0.6m/s). Determine the position and the velocity of the center of mass of the system.
Answer:
[tex]Position:(3.38m ,2.53m)[/tex]
[tex]Velocity=(1.72m/s,1.22m/s)[/tex]
Explanation:
From the question we are told that
Mass of particle 1
[tex]M_1=2.0kg[/tex]
Co-ordinate of particle 1 (2.0m,6.0m)
Velocity of Particle 1
[tex]V_1= (3.1 m / s , 2.6 m / s )[/tex]
Mass of particle 2
[tex]M_2=4.5kg[/tex]
Co-ordinate of particle 2 (4.0m,1.0m)
Velocity of Particle 1
[tex]V_2=( 1.1 m / s , 0.6 m / s )[/tex]
Generally the Position is mathematically given as
[tex]X =\frac{ ((M_1 * Cx_1) + (M_2 *Cx_2)}{(M_1 + M_2)}[/tex]
[tex]X=\frac{2*2+4.5*4}{2+4.5}[/tex]
[tex]X=3.38[/tex]
[tex]Y=\frac{(M_1* Cy_1 + M_2* Cy_2)}{(M_1 + M_2)}[/tex]
[tex]Y =\frac{(2 * 6 + 4.5 * 1)}{(2 + 4.5)}[/tex]
[tex]Y= 2.53 m[/tex]
Therefore the position is given as
[tex]Position:(3.38m ,2.53m)[/tex]
Solving for Velocity
Generally the velocity of the system is mathematically Given as
[tex]V_x =\frac{ (M_1 * vx_1 + M_2 * Vx_2)}{(M_1 + M_2)}[/tex]
[tex]V_x=\frac{ (2 * 3.1 + 4.5 *1.1)}{(2 + 4.5)}[/tex]
[tex]V_x=1.72m/s[/tex]
For Y
[tex]V_y =\frac{(M_1* vy_1 + M_2* Vy_2)}{(M_1 + M_2)}[/tex]
[tex]V_y=\frac{ (2 * 2.6) + (4.5*0.6)}{(2 + 4.5)}[/tex]
[tex]V_y=1.22m/s[/tex]
Therefore Velocity
[tex]V=(1.72m/s,1.22m/s)[/tex]
8.There are many ways to measure range of motion: goniometers, inclinometers, tape measures and even using apps on phones. In your opinion, do you think one tool is more accurate than another
Answer:
the relative error is similar in all of them, which is why they all have the same precision.
Explanation:
For this question we must be careful since there are several important concepts to take into account:
* the absolute error that is directly related to the precision or error in the mean given by the instrument
* the relative error to take into account the precision of the instrument and the magnitude of the measurement
The precisions of the different measuring instruments are
metric conta ± 0.1 cm
micrometric screw ±0.001 cm
vernier ± 0.005 cm or 0.001 cm
goniometers ± 1º
I tilt meters ± 1º
Mobile applications varies a lot, but on the order of ±0.01cm
We can see that the tape measure, the micrometric screw and the vernier are the only ones that give us a direct measurement, in the others some calculation must be made to obtain the distance reading, for which the error must also be propagated for the calculation.
We must also take into account that the vernier and micrometric screw are for short measurements only a few centimeters, the meters allow a medium to about 20 m, for measurements of more distance the other instruments are needed
If we only take into account the absolute error, the device with a smaller error is the most accurate, but this is not very correct.
The precision must be related to the magnitude of the measurement carried out, that is why the error or relative uncertainty was defined.
Let's take an example with the tape measure.
If we measure a distance of 1 cm the relative error is ±0.1, for a distance of 10 cm the relative error is ±0.01 which is very good
if we use a vernier to measure 2 cm the error is ±0.0025
if we use an inclinometer or a goniometer to measure a distance of 100 m in error it is of the order of ±0.09 m
With a cell phone it depends on the form of measurement, but all programs involve the measurement of time of a pulse of light, and assume a constant speed of light regardless of the refractive index of the medium that changes this speed. In principle this could be a very precise method, but you must know the calculation procedure and the approximations used.
As we can see, to give a correct answer we must use the relative error in this case the instruments that use the optical measurement method should be the most accurate, but the software for the calculation can involve large approximations.
Of the other instruments, the relative error is similar in all of them, which is why they all have the same precision.
As an example, a 4.00-kg aluminum ball has an apparent mass of 2.10 kg when submerged in a particular liquid: calculate the density of the liquid.
Answer:
1.2825 * 10^3 kg/m³
Explanation:
Given that :
Mass of aluminum ball (m1) = 4kg
Apparent mass of ball (m2) = 2.10 kg
Density of aluminum (d1) = 2.7 * 10^3 kg/m³
Density of liquid (d2) =?
Using the relation :
d1 / d2 = m1 / (m2 - m1)
(2.7 * 10^3) / d2 = 4 / (4 - 2.10)
2700 / d2 = 4 / 1.9
4 * d2 = 2700 * 1.9
4 * d2 = 5130
d2 = 5130 / 4
d2 = 1282.5 kg/m³
Hence, density of liquid = 1.2825 * 10^3
Unit Test
Active
11
12
13
14
15
TIME REMAININO
01:47:35
Which best describes the energy of a sound wave as it travels through a medium?
It increases
It decreases
It remains the same
It depends on the medium
Answer:
It depends on the medium is answer.
Explanation:
I hope it's helpful!
The energy of sound waves depends on the nature of medium it travels through. As the speed of the wave increases in the medium its energy increases. Hence, option d is correct.
What are sound waves ?Sound waves are type of mechanical waves passing through a medium. Sound waves are longitudinal waves hence, the oscillation of particles is in the same direction of of the wave propagation.
The energy of a wave is directly proportional to the frequency of the wave and inversely proportional to the wavelength. As the density of the medium increases, the speed of the wave decreases and thereby energy too.
Sound waves travels with higher speed through solids. As their energy increases, the waves moves with higher speed. Hence, the energy of sound waves depends on the nature of the medium.
Find more on sound waves:
https://brainly.com/question/11797560
#SPJ7
Question 1(Multiple Choice Worth 2 points)
(06.01 LC)
How can the luster of a mineral be described? by the way this is Science
A Bland
B Dim
C Dull
D Twinkle
Will get Brainlest 5 star and heart looking for someone who knows 7 grd science flvs work dm and friend
Which of these best describes Earth's crust?
A inner layer consisting of two parts
B middle layer, density increases with depth
C Top portion called asthenosphere, thickest layer
D Thinnest under the oceans and thickest under continents
"A 60 g tennis ball is dropped from a 2 m height, strikes a horizontal sidewalk and rebounds to a height of 1 m. Find the average force with which the ball hits the ground if the collision lasts 0.02s."
Answer:
F = Changing momentum / time
Explanation:
change in momentum = final momentum - initial momentum
but before finding the force we have to find the initial and final vertical velocity of the ball in both cases (1st bounce and 2nd bounce) so first let's find the vertical velocities of the ball in the first bouncehere the ball dropped - it means (initial velocity is zero 0ms-1)but there is a final vertical velocity...let's find the final vertical velocity v² = u² + 2as (here a = g = 10ms^-2)v = √0²+2(10)2v = 6.32ms^-1After that let's find the vertical velocities of the ball in the second bounceso here our final velocity is zero (because vertical velocity in maximum heigh )is zeothen let's find our initial vertical velocityv² = u² + 2as0 = u² + 2(-10)1 (here -10 cause gravitational acceleration act positive only in the downward direction )u = √20u = 4.47ms^-1ok, now we found all the velocities then let's find the forceF = Changing momentum / timechanging momentum = impulse= mv-m(-u)= 0.06 (6.32+4.47)=0.6474 Nsso we found the chang in momentumthe let's find the forceF = Changing momentum / timeF = 0.6474 / 0.02F = 32.37N