Question

17. A ball is thrown vertically up with a velocity of 50 m/s then average velocity of the body for the whole journey g = 10 m/s. 1) 9.8 m/s 2) 0.8 m/s 3) 0.2 m/s 4) O m/s​

Answer 1

Answer:

Given Initial velocity of ball, u=49 m/s

Let the maximum height reached and time taken to reach that height be H and t respectively.

Assumption: g=9.8 m/s2 holds true (maximum height reached is small compared to the radius of earth)

Velocity of the ball at maximum height is zero, v=0

v2−u2=2aH

0−(49)2=2×(−9.8)×H

⟹H=122.5 m

v=u+at

0=49−9.8t

⟹t=5 s

∴ Total time taken by ball to return to the surface, T=2t=10 s

Answer 2

Answer:

0 is the answer

Explanation:

we know that displacement is 0

because the ball after moving came to the initial point itself

avg velocity= diff in displacement/ diff in time

so if displacement is 0 then avg velocity is 0 too