Search This Blog

Google

Tuesday 2 April 2013

Q.No.3.5: - A man standing on the top of a tower throws a ball straight up with initial velocity Vi and at the same time throws a second ball straight downward with the same speed. Which ball will have larger speed when it strikes the ground ignore air friction?

Q.No.3.5: - A man standing on the top of a tower throws a ball straight up with initial velocity Vi and at the same time throws a second ball straight downward with the same speed. Which ball will have larger speed when it strikes the ground ignore air friction?
Ans: - Both balls will have same speed on striking the ground. When a body is projected vertically upward with certain initial velocity, then it will hit the ground with the same velocity. Thus, when the ball is thrown straight up with the initial velocity vi when it returns back. Hence, this ball will strike the ground with the same speed. When a second ball is thrown vertically downward with initial velocity vi it will also strike the ground with the same speed. It results that, in both the cases, the balls will hit the ground with the same speed. But the difference is that both the balls will hit the ground at different times due to different heights.

3 comments:

  1. Second ball or first ball will strike the ground first.

    ReplyDelete
  2. as it has constant acceleration i,e g=9.8m/s2 it means that velocity/speed is increases linearly every second so the second object takes more times,consequently it will hit the ground with higher speed

    ReplyDelete