Question

Please help me with this Physics 1 work sheet. Please explain !!

A block is placed in a crate. The inner surface of the crate is frictionless. The crate is pulled a distance d to the left across a level, frictionless surface by a rope that exerts a constant force of magnitude F theta. In the space below, draw and label separate free-body diagrams for the crate and the block.. Identify all the Newton's third law (action-reaction) force pairs in your diagrams by placing one or more small "X" symbols through each member of the pair. For each force depicted on your free-body diagrams, state whether that force does positive, negative, or zero work. Explain. T Consider the following statement:"The work done by the crate on the block is zero. The block doesn't slip, which means its displacement in the crate is zero."Do you agree with this statement? Explain your reasoning. Determine the sign of the net work done on the block and the crate. Explain. Is the absolute value of the net work done on the crate greater than, less than, or equal to i quantity Find? Explain your reasoning. Would your? Answer to part f differ if the block were removed from the crate? (Assume the string still exerts a force Forever a distance Explain.

Answer 1

a) CN BN BR BR СВ FC+B Crate Block b) CN BN BR BR СВ FC+B Crate Block c) Work done by forces F . -FR: Positive FBR: Negative FcN .FCB, Fc-в.F, and FB : Zero BR d) The forces acting normal to the block don't do any work at all since the force is normal to the displacement. The block doesn't slip with respect to the crate. But, to an observer Sitting outside the crate exerts a force on the block and they together move in negative x- direction. So the reaction force on the block does some work on the block Work done by the crate on the block is not zero