Question

The radius of a body moving in a circle with constant angular velocity is given by $r=4t^2$, with respect to time. What is the magnitude of the tangential velocity at t=2, if the angular velocity is 7 rad/s?

• A. 56
• B. 112
• C. 126
• D. 65

Answer 1

Answer: (B)

112

Answer 2

The tangential velocity ($v_t$) of a body moving in a circular path is given by the product of its radius ($r$) and its angular velocity ($\omega$):

$v_t = r\omega$

First, calculate the radius at $t=2$ s:

$r(t=2) = 4(2^2) = 16$

Then, calculate the tangential velocity:

$v_t = 16 \times 7 = 112$