The wheel of a car is rotating at the rate of 1200 revolutions per minute. On pressing the accelerator for 10 seconds, it starts rotating at 4500 revolutions/minute. The angular acceleration of the wheel is

Options

A. `0 ("radian")/("sec"^2)`
B. `1880("degrees")/("sec"^2)`
C. `40("radian")/("sec"^2)`
D. `1980 ("degree")/("sec"^2)`

Answer

D

Explanation

`alpha = (omega_2 - omega_1)/(t) = (2pi(n_2 - n_1))/(t), " " n_2 = (4500)/60 = 75 (rev)/(sec) , n_1 = (1200)/60= 20 (rev)/(sec)`
[Revolution = `2pi` Radian=`360^@`., `alpha = ((75 - 20))/(10) xx 360^@ ("degree")/("sec"^2) = 1980 ("degree")/("sec"^2)`