A motor car is moving with a speed of `20 ms^-1` on a circular track of radius 100cm. If its speed is increasing at the rate of `3 ms^-1`, its resultant acceleration is

Options

A. a)`3 ms^-2`
B. b)`5 ms^-2`
C. c)`2.5 ms^-2`
D. d)`3.5 ms^-2`

Answer

B

Explanation

Resultant acceleration,
`a=sqrt(a_c^2+a_t^2)`
`=sqrt((v^2/r)+(3)^2 )=sqrt(((20 times 20)/100)^2+9)`
`=sqrt(16+9)=5 ms^-2`