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

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