Centripetal
Draw the velocity, acceleration, and force vectors in circular motion
diagram
Two points on a rotating disk are at different distances from the center. What is true about the angular speeds?
They are the same
Define moment of inertia
What are the formulas for angular momentum and KE?
Iw and 1/2Iw^2
A car is speeding around a curve at 40 m/s. The radius of the curve is 22 m. What is the centripetal acceleration?
72 m/s^2
A wheel starts from rest and reaches an angular speed of 12 rad/s in 4.0 s. What is the angular acceleration?
3 rad/s^2
Which has more moment of inertia? A soccer ball of 5 kg and radius .2 m or a bowling ball of 5 kg and radius .2 m?
Soccer Ball. (2/3 vs 2/5)
Give an example of conservation of angular momentum
ice skating, wheel and chair etc
An object moves in a circle of radius 2 m in 7 seconds. What is the centripetal velocity?
1.8 m/s
A point on a rotating disk is 0.40 m from the center. The disk rotates at 6.0 rad/s. Find the tangental speed of the point.
2.4 m/s
A door is 0.90 m wide. A student pushes with a 15 N force at a point 0.75 m from the hinges at an angle of 90° to the door. Find the torque.
11.25 Nm
A 0.50 kg particle moves in a circle of radius 0.80 m at a speed of 6.0 m/s. What is the angular momentum?
2.4 kgm^2/s
The centripetal acceleration of a yo-yo being spun in a circle is 2.7 m/s. The string is .78 m long. What is the tangental speed?
1.45 m/s
A bicycle wheel of radius 0.35 m rotates at a constant 8.0 rad/s. How long does it take the wheel to rotate through 20 revolutions?
15.7 seconds
A seesaw is balanced at its center. A 400 N person sits 1.2 m to the left of the pivot. What force must a second person exert on the right side 1.5 m from the pivot to keep the seesaw in equilibrium?
320 N
A solid disk of mass 4.0 kg and radius 0.30 m rotates at 12 rad/s. What is the KE?
12.96 J
A ball on a string spins at 3 rad/s with a 0.5 m radius. What's the tangental speed?
1.5 m/s
A wheel rotating at 20 rad/s experiences an angular acceleration of –4.0 rad/s². How many revolutions does it make before stopping?
7.96 revs
The acceleration of a uniform solid disk of mass 6.0 kg and radius 0.40 m is 3 rad/s^2. Find the torque on the disk.
1.44 Nm
A point on a .45 kg soccer ball with radius .11 m has a tangential velocity of 5 m/s. What is the rotational KE?
3.75 J