Rotation

A diver can change her rate of rotation if she tucks in her head and bends her knees. lets assume that when she is streched out straight, she is rotating a 1 revolution per second. now she tucks and rolls cutting her body lenght in half, what will be her rate of rotaion now? I think it is either 5Hz or 4Hz.

Speed

A hoop of 0.5m and a mass of 0.2kg is released from rest five meters above the horizontal and allowed to roll down an inclined plane. How fast is it moving when it is 2 meters above the horizontal?

Torque

A wheel with rotational inertia of 8.0kg-m^2 and rotational kinetic energy of 155 joules requires what torque to bring it to rest in 4.0 seconds?

Magnitude

A force is applied to the end of a 2.0ft long, uniform board weighing 50lbs. in order to keep it horizontal and stationary while it pushes against the wall at the left. if the angle the force makes is 30 degrees towards the left, what is the magnitude of the applied force F?

Ratio of inertia

Consider two uniform solid spheres with the same diameter, but one has twice the mass of the other. The ratio of the larger moment of inertia to that of the smaller moment of inertia is what?

A solid ball, solid cylinder and a hollow pipe all have equal masses and radii...

A solid ball, solid cylinder and a hollow pipe all have equal masses and radii. All three are released simultaneoulsy from the top of an inclined plane, which will reach the bottom frist. Is it none of the above, the cylinder, the ball or the pipe?

Three Physics Problems

(See attached file for full problem descriptio with proper symbols) --- Two ice skaters, with masses of 50.0 and 75.0 , are at the center of a 40.0 -diameter circular rink. The skaters push off against each other and glide to opposite edges of the rink. a.) If the heavier skater reaches the edge in 10.0 , how long does ...continues

Balls A and B roll across a table, then collide elastically. The paths of the two balls are pictured (viewed from above) in the diagram.

Balls A and B roll across a table, then collide elastically. The paths of the two balls are pictured (viewed from above) in the diagram. (See attachment for diagram)

Collision in one dimension

(See attached file for full problem description with diagrams and units) --- On a frictionless horizontal air table, puck A (with mass 0.369 ) is moving toward puck B (with mass 0.249 ), which is initially at rest. After the collision, puck A has velocity 0.116 to the left, and puck B has velocity 0.645 to the right. ...continues

Two ice skaters, with masses of 50.0 kg and 75.0 kg...

(See attached file for full problem description with units) --- Two ice skaters, with masses of 50.0 and 75.0 , are at the center of a 40.0 -diameter circular rink. The skaters push off against each other and glide to opposite edges of the rink. a.) If the heavier skater reaches the edge in 10.0 , how long does the lig ...continues