Question 78: Centre of Mass and Rotational Motion

Question

The wheel of a car, accelerated uniformly from rest, rotates through 5 radians during the first second. The angle (in radians) rotated during the next second is

Accepted Answer

From 2nd equation of rotational motion,
$$	heta  = {\omega _0}t + {1 \over 2}\alpha {t^2}$$
Given, $$	heta$$ = 5 rad, t = 1s, $$\omega$$
0
= 0
Substituting all these values in above equation, we get
$$5 = 0 + {1 \over 2}\alpha {(1)^2} \Rightarrow \alpha  = 0$$ rad/s
2
The angle rotated by wheel of car during first two seconds,
$${	heta _2} = 0 + {1 \over 2} + \alpha {t^2} = {1 \over 2} 	imes 10 	imes {2^2} = 20$$ radians
Hence, angle rotated during the 2nd second
= $$	heta$$
2
= 0
= 2 $$-$$ 5 = 15 radians

Answer

15

Answer

7.5

Answer

12.5

Answer

20

Centre of Mass and Rotational Motion

The wheel of a car, accelerated uniformly from rest, rotates through 5 radians during the first second. The angle (in radians) rotated during the next second is

Choose the correct answer: