Question

A ball rolls off a horizontal table with velocity v. = 5 m/s. The ball collides elastically from a vertical
wall at a horizontal distanceD=8 m) from the table, as shown in figure. The ball then strikes the floor a
distance x, from the table (g = 10 m/s2). The value of x, is
Vo=5m/s
h=20m
DELETE
(A) 6 m
(B) 4 m
(C) 5 m
(D) 7 m
BER​

Answer 1

The speed of the ball is 5 m/s

Explanation:

A ball rolls off the edge of a horizontal table top 4 m high. If it strikes the floor at a point 5 m horizontally away from the edge of the table, what was its speed at the instant it left the table?

Using second equation of motion:

h = 1/2 gt^2

We have:

h (AB) =1/2 gt^2 (AB)

t (AC) = √ 2 h (AB) / g

t (AC) = √ 2 x 4 / 9.8

t (AC)  = 0.9 second

further BC = vt (AC)

v = BC / t (AC) = 5.0 / 0.9 =5.5 m/s

thus the