calculate the velocity of a body released from 40m heigh when it touches the ground (g=9.8m/s^2)
(1)38m/s
(2)46m/s
(3)28m/s
(4)48m/s
Answers
Answered by
1
Explanation:
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/s
2
holds true (maximum height reached is small compared to the radius of earth)
Velocity of the ball at maximum height is zero, v=0
v
2
−u
2
=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
Answered by
0
Answer:
28 m /s
Explanation:
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