A chair of mass 16.0 kg is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force F = 43.0 N that is directed at an angle of 42.0 ∘ below the horizontal and the chair slides along the floor. Use Newton's laws to calculate the normal force that the floor exerts on the chair.

Energy is the ability to do work which measures what

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?

Abanked road comer of radius 146 m is to be constructed. if the comer is designed for vehicles moving with a speed of 20.0 m/s, what should the banking angle be, in units of degrees?