A particle has initial A particle has initial velocity `10m//s`. It moves due to constant retarding force along the line of velocity which produces a retardation of `5 m//s^(2)`. Then

Options

A. the maximum displacement in the direction of initial velocity is 10 m
B. the distance travelled in first 3 second is 7.5 m
C. the distance travelled in first 3 second is 12.5 m
D. the distance travelled in first 3 second is 17.5 m

Answer

B,C

Explanation

`vec(F)_("net")=vec(F)_(1)+vec(F)_(2)+vec(F)_(3)=(p+1)hat(i)+4hat(j)`
`|vec(F)_("net")|=sqrt((p+1)^(2)+4^(2))=5`
`(P+1)^(2)=25-16`
`(P+1)^(2)=9`
`P+1=pm3`
`P=-4 " or "p=2`