Question

A hurdler is 0.635 m from a hurdle when he jumps at 3.22 m/s at a 62.9° angle. How many seconds later does he clear the hurdle? (Hint: it is not necessarily at the highest point in his motion.) Unit = s

Answer 1

The time taken to clear the hurdle is: 0.433 s .

How to find the Time Taken?

The horizontal distance of the hurdle = 0.635 m

This distance covered by the hurdler is given by horizontal component of his velocity as:

Horizontal component of hurdler's initial velocity = 3.22 * cos 62.9

Horizontal component of hurdler's initial velocity = 1.4668 m /s

Displacement in horizontal direction = 0.635 m

Acceleration = 0 m/s² as no force acts in horizontal direction .

So time taken to clear the hurdle = 0.635/1.4668 s

= 0.433 s .