Question

A ball is thrown vertically upward with a speed of 21.0 m/s.
(a) How high does it rise?
m

(b) How long does it take to reach its highest point?
s

(c) How long does the ball take to hit the ground after it reaches its highest point?
s

(d) What is its velocity when it returns to the level from which it started?

Answer 1

Answer:

a). 22m

b). 2.1 sec

c). 20.9 m/sec

d). 2.01 sec

Explanation:

a). v²= u²+ 2as

as it reach to higest point its velocity became zero so, v=o

o=21×21+2(10)(s)

s=22m

b). v=u+at

0=21+(10)(t). ( v=o)

t=2.01 sec

c). v²= u²+2as

v²=o+2(10)(22)

v= 20.9

d). v=u+at

20.9=10(t)

t=2.09