Question

1.If a wheel is turning at 7.7rad/s, the time (in seconds) it takes to complete one revolution is about:

Select one:

a. 0.82

b. 2.5

c. 48

d. 24

e. 0.41

2.A flat (unbanked) curve on a highway has a radius of 222.8m. A car rounds the curve at a speed of 27.6m/s. What is the minimum coefficient of friction that will prevent sliding?

3.Suppose a stationary 52.5-kg box is on top of your table. What is the work done by gravity?

Select one:

a. 52.50 J

b. 0 J

c. 9.8 J

d. 514.50 J

Answer 1

1. $T=2\pi/\omega=0.82\text{ s}.$

2. $\mu=v^2/(gR)=0.35.$

3. $W=0.$