Physics Past Questions and Answers

A rope is being used to pull a mass of 10kg vertically upward. Determine the tension in the rope if, starting from rest, the mass acquires a velocity of 4ms\(^{-1}\) in 8s [g = 10ms\(^{-2}\)]

I. The frictional force is independent of the area of the surfaces in conduct
II. The frictional force depends on the nature of the surfaces in contact
III. The frictional force depends on the speed of sliding
IV. The frictional force is directly proportional to the normal reaction.
Which combination of the above is true of sliding friction?

Total internal reflection occurs when light moves from

A quantity of water at 0°C is heated to about 30°C. At each degree rise in temperature, its density will

I. Coherence
II. Same frequency
III. Same wavelength
IV. Same Intensity
Which of the conditions above are necessary to produce interference fringes?