Question

A stone is thrown at an angle of `53^@` and it reaches its highest point in `2` seconds. What is its velocity at the highest point?

Answer 1

Velocity at highest point is `14.77` m/s.

Explanation:

Let the velocity of the stone, when stone makes an angle of `53^@` be `u` m/s,

then its horizontal component is `ucos53^@` and vertical component is `usin53^@`.

In such case while gravity slows down vertical component (in `2` seconds) to `0`, there is no impact on horizontal component (assuming there is no aair frition slowing it down, which is an assumption while answering such questions).

Hence `usin53^@-9.8xx2=0` i.e. `uxx0.79864=9.8xx2`

or `u=19.6/0.79864=24.542` m/s.

and hence at highest point the stone will only have horizontal component i.e. `24.542xxcos53^@=24.542xx0.6018=14.77` m/s.