Physics 218 Mechanics Instructor Dr Tatiana Erukhimova Lectures

Physics 218: Mechanics Instructor: Dr. Tatiana Erukhimova Lectures 11, 12

Coefficient of friction: V 0=0 βt H Find the equation that could be solved to find the velocity of the block when it reaches the top.

A block of mass 20 kg is pushed against a vertical surface as shown. The coefficient of friction between the surface and the block is 0. 2. If θ=300, what is the minimum magnitude of P to hold the block still? P θ

A wedge with mass M rests on a frictionless horizontal tabletop. A block with mass m is placed on the wedge and a horizontal force F is applied to the wedge. What must the magnitude of F be if the block is to remain at a constant height above the tabletop?

A Problem With First Year Physics Strings and Pulleys m 1, m 2 are given m 2>m 1 String is massless and unstretchable m 2 Find accelerations of m 1 and m 2 (assume no friction in pulley)

Block 1, of mass m 1, is placed at rest on an inclined plane. It is attached by a massless, unstretchable string to block 2, of mass m 2. The pulley is massless and frictionless and just changes the direction of the tension in the string. The coefficient of friction between the plane and m 1 is the constant . 1 2 Determine what range of values for mass m 2 will keep the system at rest. Find acceleration if mass 2 goes down.

Friction everywhere. 2 F 1 Find F necessary to drag the box 1 at constant speed.

The advantage of a pulley What minimum force F is needed to lift the piano of mass M?

The Elevator Problem

Have a great day! Reading: Chapters 5, 6