Joey drags his 25kg brother across the floor with a force of 12 N to the right at a constant velocity. Determine the normal force and the frictional force applied to the little brother. Draw the force diagram before solving the problem.

Aman tries to push a box of mass 4 kg with a force of 5 n but the box remains stationary if the coefficient of static friction is 0.45, what is the value of the maximum force of friction?

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane