Question

A ball is dropped from the height of 20 m. Calculate i)the time taken by the ball to reach the ground, and ii) the velocity with which the ball strikes the ground.

Answer the question correctly otherwise it will be reported.​

Answer 1

Answer:

here's your answer dear

we know,

s=h=20

a=g=±10m/s=10m/s (since it is dropped)

v^2-u^2= 2as

v^2=2x10x20 (u=0; it is dropped not thrown)

v=20m/s

for calculating time

we know,

v=u+at

20= 0+ 10xt

t=2seconds

thus, it will attain a speed of 20m/s before touching the ground, but the time taken to reach the ground is 2seconds. Because the velocity is not uniform but acceleration/gravity is. If still there is any confusion. Try the same problem with 80 of height.

Answer 2

we know,

s=h=20

a=g=±10m/s=10m/s (since it is dropped)

v^2-u^2= 2as

v^2=2x10x20 (u=0; it is dropped not thrown)

v=20m/s

for calculating time

we know,

v=u+at

20= 0+ 10xt

t=2seconds

thus, it will attain a speed of 20m/s before touching the ground, but the time taken to reach the ground is 2seconds. Because the velocity is not uniform but acceleration/gravity is. If still there is any confusion. Try the same problem with 80 of height.