The x and y coordinates of the particle at any time are `x=5t-2t^(2) and y=10t` respectively, where x and y are in meters and t in seconds. The acceleration of the particle at t=2s is:

Options

A. 0
B. `5m//s^(2)`
C. `-4m//s^(2)`
D. `-8m//s^(2)`

Answer

C

Explanation

`x=5t-2t^(2)" "y=10t`
`(dx)/(dt)=5-4t" "(dy)/(dt)=10`
`v_(x)=5-4t" "v_(y)=10`
`(dv)/(dt)x=-4" "(dv)/(dt)y=10`
`a_(x)=-4 " "a_(y)=0`
Acceleration of particles at t=2s is `=-4 m//s^(2)`