Question

A ball dropped from a certain height, falls in the influence of uniform gravity, strikes the ground and repeatedly rebounds elastically. During a time interval t = 8s from it was dropped, it covers a distance s = 20m. How many collisions n during this time did the ball made with the ground? Acceleration of free fall is g = 10 m/s2
ANSWER IS 8 COLLISIONS
CAN U PLEASE EXPLAIN IN DETAIL

Answer 1

Answer on Question #60130-Physics-Mechanics-Relativity

A ball dropped from a certain height, falls in the influence of uniform gravity, strikes the ground and repeatedly rebounds elastically. During a time interval $t = 8s$ from it was dropped, it covers a distance $s = 20m$ . How many collisions $n$ during this time did the ball made with the ground? Acceleration of free fall is $g = 10\frac{m}{s^2}$

Solution

$n$ collisions $\rightarrow$ 2n times a ball covers a distance $h$ .

$$h = \frac {s}{2 n}.$$ $$\tau = \frac {t}{2 n}$$ $$h = \frac {g t ^ {2}}{2} \rightarrow \frac {s}{2 n} = \frac {g}{2} \left(\frac {t}{2 n}\right) ^ {2}$$ $$n = \frac {g t ^ {2}}{4 s} = \frac {1 0 \cdot 8 ^ {2}}{4 \cdot 2 0} = 8.$$

Answer: 8.

https://www.AssignmentExpert.com