In winter why do water tanks start freezing from surface and not from bottom

The force of replusion between two like charged particles will increase if

In the classic 1960s science-fiction comic book The Atom, a physicist discovers a basketball-sized meteorite (about 12 cm in radius) that is actually a fragment of a white dwarf star.

How often does the moon go through an entire set of phases

Is the electric field contributed by the polarization charges on the surface of the metal sphere?

A 0.1 kg magnet is floating above a second magnet. The magnetic force on the 0.1 kg magnet is A) 0 N. B) 0.1 N. C) 1 N. D) 10 N.

A liquid filled sealed system has cylinders with movable pistons on each end. The face of one piston has an area of 5 cm². The other piston has an area of 500 cm² and is supporting a weight of 2 kN on it.

A turntable is spinning on a frictionless axle when a ball of putty is dropped onto it from above. The putty sticks to the turntable when it lands. Is angular momentum conserved for the turntable and putty (the system) during this process?

A cheetah can run from 0 to 70 mph in 2.2 seconds. what is the cheetah's top speed in m/s?

Which statement about how light travels is true? A Light waves need a medium to travel, and they travel at the same speed even if the light source is moving.

Explain why the car reaches a top speed even though the thrust Force remains constant at 3500N