1) A car is traveling down the interstate at 37.1 m/s. The driver sees a cop and quickly slows down. If the driver slows to 29.8 m/s in 3 seconds, what is the acceleration of the car?

2) While cleaning you lift an 87.3 N box up to a shelf that is 2.04 m above the ground. How much work was done on the box?

3) A child runs up the stairs and does 1250 J of work. If the child generates 267 W of power how long did it take for the child to run up the stairs?

Question

Physics

Scott Bradford

4 September, 02:01

1) A car is traveling down the interstate at 37.1 m/s. The driver sees a cop and quickly slows down. If the driver slows to 29.8 m/s in 3 seconds, what is the acceleration of the car?

2) While cleaning you lift an 87.3 N box up to a shelf that is 2.04 m above the ground. How much work was done on the box?

3) A child runs up the stairs and does 1250 J of work. If the child generates 267 W of power how long did it take for the child to run up the stairs?

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Answers (1)

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Leila · Answer 1

1. Acceleration is the change in velocity over time.

a = Δv / Δt

a = (29.8 m/s - 37.1 m/s) / 3 s

a = - 2.43 m/s²

2. Work equals force times distance.

W = Fd

W = (87.3 N) (2.04 m)

W = 178 J

3. Power is work per time.

P = W / t

267 W = 1250 J / t

t = 4.68 s