Question

A particle moves along a circle of radius $\left(\frac{20}{\pi }\right)$m with constant tangential acceleration. If the speed of the particle is $80$m/s at the end of the second revolution after motion has begun, the tangential acceleration is?

• A. $160\pi m/s^2$
• B. $40\pi m/s^2$
• C. $40m/s^2$
• D. $640\pi m/s^2$

Answer 1

The correct option is B $40\pi m/s^2$

Total distance travelled$=2\pi r\ast 2$(for 2 revolution)

$=S=2\times 2\pi \times 20/\pi =80m⟹\left(1\right)$

Nowbyusingtheformulae$v^2-u^2=2aS$

$(80{)}^2=2a80.(from1)$

$a=80\times \frac{80}{2}\times 80=40m/s^2$