Question 138: Motion in 1D

Question

A ball is thrown vertically downward with a velocity of 20 m/s from the top of a tower. It hits the ground after some time with a velocity of 80 m/s. The height of the tower is : (g = 10 m/s
2
)

Accepted Answer

From the Kinematic equation
v
2
= u
2
+ 2gh
v = 80 m/s
u = 20 m/s
h = $${{{v^2} - {u^2}} \over {2g}}$$
$$ = {{6400 - 400} \over {20}}$$
= 300 m

Answer

340 m

Answer

320 m

Answer

300 m

Answer

360 m

Motion in 1D

A ball is thrown vertically downward with a velocity of 20 m/s from the top of a tower. It hits the ground after some time with a velocity of 80 m/s. The height of the tower is : (g = 10 m/s 2 )

Choose the correct answer: