Two forces `F_(1)` and `F_(2)` are applied simultaneously on a `2kg` block resting on a frictionless horizontal ground. The forces vary with time according to graphs shown and cease to act after `8s`. What maximum speed `(i nm//s)` does the block acquire?

Options

A. `3`
B. `4`
C. `0`
D. `16`

Answer

B

Explanation

Ans (3)
Net force `F=F_(1)-F_(2)=8-t-4=4-t`
Net force is positive till `t=4`, therefore maximum velocity is at `t=4s`
Acceleration `a=(F)/(m)=2-(1)/(2)`

`v_(4)-v_(0)=(1)/(2)xx2xx4,v_(4)=4m//s`