Atrunk of mass 16 kg is on the floor. the trunk has a very small initial speed. the acceleration of gravity is 9.8 m/s 2 . what constant horizontal force pushing thetrunk is required to give it a velocity of 10 m/s in 20 s if the coefficient of sliding friction between the trunk and the floor is 0.57? answer in units of n.

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?

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a.a piece of paper b.a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

The necleus of an atom is made up of what subatomic particles?