hockey puck

During a hockey game, a puck is given an initial speed of 12.00 m/s. It slides 54.00 m on the ice before it stops. What is the coefficient of kinetic friction between the puck and the ice?

Problem relating to centroid

The asking problem: For the semiannular area, determine the ratio of r1 to r2 for which the centroid of the area is located at x=-1/2*r2 and y=0. Note: This problem is a 2D problem and not a 3D. It was taken from the «Distributed forces: Centroids and Centers of Gravity» section of my static course. The files is in word97 format for PC and not for Mac. So, my question is how can I find this ratio of r1 to r2? I have none idea about that!! If you will check your answers: The response is 0.520

About a problem relating to rigid body in equilibrium

The asking problem: The uniform rod AB lies in a vertical plane. Its ends are connected to rollers which rest against frictionless surfaces. Determine the relation between the angles teta and alpha when the rod is in equilibrium. Note: This is a 2D problem and not a 3D. It was taken from the «Statics of Rigid Bodies in Two Dimensions» section of my static course. The files is in word97 format for PC and not for MAC. And this is all that I have as background information. My question is, how can I determine this relation in keeping with the equilibrium equation. I have none idea for this.

Projectile problem

On a distant planet, golf is just as popular as it is on earth. A golfer tees off and drives the ball 3.5 times as far as he would have on earth, given the same initial velocities and launch angles on both planets. The ball is launched at a velocity of 45m/sec at an angle of 29 degrees above the horizontal. On the distant planet, what is the maximum height? and the range of the ball?

Working with projectile motion.

William Tell must split the apple atop his son's head from a distance of 27 meters. When he aims directly at the apple, the arrow is horizontal. At what angle must he aim the arrow to hit the apple if the arrow travels at a speed of 35m/sec?