How long would it take a planet to orbit the Sun if it’s semi-major axis was 5x smaller than Earth’s? Give your answer in days.

Ablock having mass m slides down an inclined plane. the force of friction between the block and the inclined plane is f, the block's weight is m g, and the normal force is n. (a) draw a free – body force diagram showing the forces acting on the block. (b) write down all relevant newton’s equations for a given situation.

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?