Question

A particle starts from the origin with a velocity of `10 m s^(-1)` and moves with a constant acceleration till the velocity increases to `50 ms^(-1)`. At that instant, the acceleration is suddenly reversed. What will be the velocity of the particle, when it returne to the starticng point?
A. Zero
B. `10ms^(-1)`
C. `50 ms^(-1)`
D. `70 ms^(-1)`

Answer 1

Correct Answer - D
`2ax=(50)^(2)-(10)^(2)` and `2(-a)(-x) =v^(2)-(50)^(2)`
This gives `v^(2)-(50)^(2) =(10)^(2)` i.e. `v=70 ms^(-1)`.