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when starting a foot race, a 64.5 kg sprinter exerts an average force of 655 n backward on the ground for 0.75 s. what is his final speed

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User BowPark
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1 Answer

7 votes

Answer:

The final speed of the sprinter would be approximately 7.61 m/s.

Step-by-step explanation:

We can use Newton's second law of motion and one of the equations of motion to solve for the final speed of the sprinter.

F = m * a

Where:

F = Force

m = Mass

a = Acceleration

We can rearrange this equation to solve for acceleration:

a = F / m

In this case, the force exerted by the sprinter is the net force because there is no other force acting on him/her horizontally. So we have:

a = 655 N / 64.5 kg ≈ 10.15 m/s^2

Next, we can use the one of the equations of motion to find the final speed of the sprinter. The equation we need is:

v_f = v_i + a * t

where:

v_f = the final speed

v_i = the initial speed (which is zero in this case)

a = the acceleration

t = the time interval

We can enter in the values we calculated:

v_f = 0 + (10.15 m/s^2) * (0.75 s) = 7.6125 m/s

Rounding to 2 decimal places, the final speed of the sprinter is approximately 7.61 m/s.

answered
User Mate Zabo
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