Working with force and mechanical advantage.

A 1m long crowbar is used to lift a heavy crate. The pivot point is 10 cm from one end. a) If 600 N is exerted on one end, what is the upward force exerted on the crate at the other end? b) Calculate the mechanical advantage, the ratio of forces.

Find by integration the moment of inertia of a uniform, hollow cylinder.

A uniform hollow cylinder such as a roll of paper towels, has mass M, inner radius Ri, outer radius Ro. By applying 'I= Int (r^2 dm)', find its moment of inertia about a center of mass axis along its diameter. SEE ATTACHMENT PDF #1 FOR DIAGRAM OF THE CYLINDER

Mass and density of system

Determine the mass of wire having a relative density of 8.77 which must be wrapped around a cork weighing 15 g in order that the cork shall just sink in fresh water. The cork's relative density=0.24.

Calculating coefficient of friction and how far a spike goes into the ground

1a) A steel block with a mass of 62 kg is drawn along a horizontal surface. It is pulled by a rope that is 27 degrees above the horizontal with a 73 N force. What is the coefficient of friction? Assume the object is moving at a constant speed. 1b) A block of steel weights 1.5 ton and is allowed to fall 1.5 m on to a spike. ...continues

'Net torque = I alpha' applied to a hollow cylinder with force applied tangentially.

A roll of paper towels is a uniform hollow cylinder, mass M=.75 kg, outer radius Ro=.084 m, inside radius of the hollow core Ri=.036 m. The roll is mounted on frictionless bearings. See attachment #1 for a picture showing parameters. By pulling on the paper towel with a tangential force P=.25 nt, starting at rest, the roll is ...continues

Sphere and Cylinder having different accelerations down a plane.

At the upper end of an inclined plane of length L, a uniform sphere is released from rest. At the same instant, a uniform cylinder is released from rest at distance d ahead of the sphere such that both sphere and cylinder arrive at the same time at the lower end of the plane. a. The distance d is what fraction of length L? b. ...continues

Normal Force for car on incline

A 3,000 lb car is parked a an angle of 30 degrees, facing uphill. The center of mass of the car is halfway between the front and rear wheels and is 2ft above the ground. The wheels are 8ft apart. Find the normal force exerted by the road on the front wheels and the rear wheels.

Falling Stick

A uniform stick of mass M and length l is suspended horizontally with end B on the edge of a table, and the other end, A is held by hand. Point A is suddenly released. At the instant after release: a) What is the torque about B? b) What is the angular acceleration about B? c) What is the vertical acceleration of the center ...continues

Working with rotational motion of a mass on a string about a rod.

Mass m is attached to a post with radius R by a string. Initially, the mass is a distance r from the center of the post and is moving tangentially with a speed Vo. In case (a) the string passes through a hole in the center of the post at the top. The string is gradually shortened by drawing it through the hole. Case (b) the spri ...continues

Calculating the amount of torque required to keep a cylinder rotating in a uniform V grove.

A cylinder of mass M and radius R is rotated in a uniform V grove (which looks like a rectangular block with an 45-45-90 degree triangular prism cut from the center- that the cylinder rotates in) The cylinder has a constant angular velocity w and a coefficient of friction u with each surface. What torque must be applied to the c ...continues