Question 7: Indicate which of the forces do not perform work on the box and explain why: FBD KD WEIGHT PULLING FORCE mv FRICTIONAL FORCE NORMAL FORCE

3) The figure below illustrates a skier who is skiing on a large frictionless spherical ball of snow. The skier can be treated as a point-like object. The skier starts at the top of the ball with very little speed and picks up speed while traveling along the surface of the snow. During this time, the only forces acting on the skier are the gravitational force applied by the Earth and the normal force applied by the snow. At the moment the radial line extending from the skier to the center of the ball defines an angle a with respect to a vertical line, the skier is about to lose contact with the ball. Determine the value of a.

Need help with #12 please

n a carbon monoxide (CO) molecule, the distance between the oxygen atom and the carbon atom is 1.13 × 10-10 meters. The mass of an oxygen atom is 16 atomic mass units (amu) and the mass of a carbon atom is 12 amu. How far from the oxygen (O) atom is the center of mass of the molecule, in meters? Justify your answer using your equations and rationale used.

When do you use W = Fdcostheta when solving for work and in what situations will you use W = Fd?