Why do physicists use models?

One might imagine that if energy generation by nuclear fusion were to increase in a star, this would heat the gas, which would in turn increase the rate of nuclear fusion, and so forth in a runaway cycle of increasing temperature.

How do I find angular speed of a rotating mass

The 20 C electricity has passed through the coil of the 230 V iron in 4 seconds Calculate the electrical resistance of this spiral.

A train has a constant velocity of 2 m/s east. What is the magnitude of the horizontal acceleration of the train?

In 1600, Dr. William Gilbert coined the term "electrica," a word that gave rise to our word electricity. What does this term "electrica" describe?

An astronaut weighs 104 newtons on the moon, where the strength of gravity is 1.6 newtons per kilogram. What would she weigh on Mars?

A chemical bond formed when Adams share three pairs of electrons is A. an ionic bond B. a single bond C. a double bond D. a Triple bond

A 1100 kg car rounds a circular turn of radius 24.6 m. Of the road is flat and the coefficient of static friction between the tires and the road is 0.59, how fast can the car go without skidding

What is the momentum of a 15 kg tire rolling down a hill at 3 m/s? 5 kg • m/s 18 kg • m/s 45 kg • m/s 60 kg • m/s

Which of Newton's laws, when combined algebraically with his law of universal gravitation, can be used to calculate Earth's mass? A) first B) second C) third