Question

24. A ball is thrown vertically up with a velocity of
4.9 m/s. The ball is then collected by the person on
ground after a time interval of
(a) 3.0 s (b) 2.0 s (c) 1.0 s (d) 0.5 s​

Answer 1

Answer:

c)1s

Explanation:

a=-9.8m/s^2

u=4.9m/s

v=0m/s

.°.v=u+at

0=4.9-9.8×t

-4.9=-9.8t

t=1/2s

s=ut+1/2at^2

s=4.9×1/2-1/2×9.8×1/2^2

s=4.9/2-4.9×1/4

s=9.8-4.9/4

s=4.9/4m

u=0m/s

a=9.8m/s^2

s=ut+1/2at^2

4.9/4=0×t+1/2×9.8×t^2

4.9/4=4.9×t^2

t^2=1/4

t=√1/4

t=1/2s

.°.total time =1/2+1/2=1s

Answer 2

2seconds

Because when it goes up it takes 1sec and again it comes in a same speed