Question

Suppose you are asked to find the amount of time t, in seconds, it takes for the turntable to reach its final rotational speed. Which of the following equations could you use to directly solve for the numerical value of t?
A) θ=θ0+ω0t+(1/2)αt2
B) ω=ω0+αt
C) ω2=ω02+2α(θ−θ0)
D) More information is needed before t can be found.

Answer 1

Answer:

option (D)

Explanation:

Here initial rotation speed is given, final rotation speed is given and asking for time.

If we use

A) θ=θ0+ω0t+(1/2)αt2

For this equation, we don't have any information about the value of angular displacement and angular acceleration, so it is not useful.

B) ω=ω0+αt

For this equation, we don't have any information about angular acceleration, so it is not useful.

C) ω2=ω02+2α(θ−θ0)

In this equation, time is not included, so it is not useful.

D) So, more information is needed.

Thus, option (D) is true.