←
Problems

Problems

6.1 Angle of Rotation and Angular Velocity

16 .
What is the angle of rotation (in degrees) between two hands of a clock, if the radius of the clock is 0.70 m and the arc length separating the two hands is 1.0 m ?
  1. 40 ∘
  2. 80 ∘
  3. 81 ∘
  4. 163 ∘
17 .
A clock has radius of 0.5 m . The outermost point on its minute hand travels along the edge. What is its tangential speed?
  1. 9 × 10 − 4 m/s
  2. 3.4 × 10 − 3 m/s
  3. 8.5 × 10 − 2 m/s
  4. 1.3 × 10 1 m/s

6.2 Uniform Circular Motion

18.

What is the centripetal force exerted on a 1,600 kg car that rounds a 100 m radius curve at 12 m/s?

  1. 192 N
  2. 1, 111 N
  3. 2, 300 N
  4. 13, 333 N
19.

Find the frictional force between the tires and the road that allows a 1,000 kg car traveling at 30 m/s to round a 20 m radius curve.

  1. 22 N
  2. 667 N
  3. 1, 500 N
  4. 45, 000 N

6.3 Rotational Motion

20.

An object’s angular acceleration is 36 rad/s2. If it were initially spinning with a velocity of 6.0 rad/s, what would its angular velocity be after 5.0 s?

  1. 186 rad/s
  2. 190 rad/s2
  3. −174 rad/s
  4. −174 rad/s2
21.

When a fan is switched on, it undergoes an angular acceleration of 150 rad/s2. How long will it take to achieve its maximum angular velocity of 50 rad/s?

  1. −0.3 s
  2. 0.3 s
  3. 3.0 s