Question

Mary is at the top of a 25 m steep slide. She is then pushed and starts accelerating at a rate of 4.3 m/s"2. How long will it take her to get to the bottom of the slide? 

Answer 1

Answer

3.4 s

Explanation

The question can be solve by using the 2nd Newton's law of motion.

s = ut + 1/2at²

Before she is pushed, the  initial velocity is zero.

u = 0

Now the equation becomes

s = 0 + 1/2at²

s = 1/2at²

25 = 1/2 × 4.3 × t²

50 = 4.3t²

t² = 50/4.3

  = 11.628

t = √11.628

   = 3.4 s