A car is moving along a circular arc at a speed of 20 ms! The radius of the arc is 10 m. If the speed is increased at the rate of 30`ms^(-2)`, what is the resultant acceleration ?

Options

A. `10ms^(-2)`
B. `50ms^(-2)`
C. `70ms^(-2)`
D. `250ms^(-2)`

Answer

B

Explanation

Here `a_(r)=(v^(2))/(r )=(20xx20)/(10)=40ms^(-2)`
`a_(r )=30ms^(-2)`
`a=sqrt(a_(r )^(2)+a_(t)^(2))=sqrt(30^(2)+40^(2))`
=`50ms^(-2)`