What's a Scientific law

Dina has a mass of 50 kilograms and is waiting at the top of a ski slope that's 5.0 meters high.

Although one can electrify a glass rod by rubbing it with silk, no net charge is created. a. True b. False

The decibel scale measures A. the loudness of sound B. the frequency of sound C. the pitch of sound D. the wavelength of sound

To produce electricity, a generator needs what kind of input? a) a magnetic field b) a moving rod c) mechanical energy d) electrical energy

How long must a current of 100mA flow so as to transfer a charge of 80 C?

People have proposed driving motors with the earth's magnetic field. This is possible in principle, but the small field means that unrealistically large currents are needed to produce noticeable torques.

A hot air ballon with a mass of 500kg ascends at a constant rate of 1.5 m/s for 20s. how much work is done by the upward force?

A construction team gives an estimate of three months to repave a large stretch of a very busy road. The government responds that it's too much inconvenience to have this busy road obstructed for three months, so the job must be completed in one

Determine the time needed for the load at b to attain a speed of 10 m/s, starting from rest.

A tea kettle is warmed on an electric stove. After a while, water vapor builds inside the kettle and causes a whistle in the lid to make a sound. How does this demonstrates the first law of thermodynamics?