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hjlf
3 years ago
5

An object is falling from a height of 7.5 meters. At what height will its velocity be 7 meters/second?

Physics
1 answer:
Ivanshal [37]3 years ago
8 0

Answer:

5.0 m

Explanation:

The velocity of the object at time t is given by

v=at

where a=9.8 m/s^2 is the acceleration of gravity and t is the time. If we substitute v=7 m/s, we can find the time t at which the velocity became 7 m/s:

t=\frac{v}{a}=\frac{7 m/s}{9.8 m/s^2}=0.71 s

The height of the object at time t, h(t), is given by the equation

h(t)=h_0 -\frac{1}{2}at^2

where h_0 = 7.5 m is the initial height. By substituting t=0.71 s inside the equation, we find the height h(t) at which the velocity is 7 m/s:

h(0.71 s)=7.5 m- \frac{1}{2}(9.8 m/s^2)(0.71 s)^2=5.0 m

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Explanation: I think...

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7 0
3 years ago
CONFUSED!!!
otez555 [7]

A. Impulse is simply the product of Force and time. Therefore,

I = F * t                                 ---> 1

where I is impulse, F is force, t is time

 

However another formula for solving impulse is:

I = m vf – m vi                    ---> 2

where m is mass, vf is final velocity and vi is initial velocity

 

Therefore using equation 2 to solve for impulse I:

I = 2000kg (0) – 2000kg (77 m/s)
I = -154,000 kg m/s

 

B. By conservation of momentum, we also know that Impulse is conserved. That means that increasing the time by a factor of 3 would still result in an impuse of -154,000 kg m/s. So,

I = F’ * (3 t) = -154,000 kg m/s

Since t is multiplied by 3, therefore this only means that Force is decreased by a factor of 3 to keep the impulse constant, therefore:

(F/3) (3t) = -154,000 kg m/s

 

 

Summary of Answers:

A. I = -154,000 kg m/s

B. Force is decreased by factor of 3

8 0
3 years ago
The distance between Pluto and the Sun is 39.1 times more than the distance between the Sun and Earth. Calculate the time taken
german

Answer:

Explanation:

Given

Distance between Pluto and sun is 39.1 times more than the distance between earth and sun

According to Kepler's Law

T^2=kR^3

where k=constant

T=time period

R=Radius of orbit

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so Distance between Pluto and sun is R_2=39.1\cdot R_1

T_1 and T_2 is the time period corresponding to R_1 and R_2[/tex]

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divide 1 and 2

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T_2^2=365^2\times 39.1^3

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7 0
3 years ago
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dusya [7]
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