What is the size of the gravitational force acting on the sun due to the earth?

a. What is the gravitational force of the sun on the earth? b. What is the gravitational force of the moon on the earth? c. The moon's force is what percent of the sun's force?

When one 20 g mass is supported by two of these vertical, parallel springs (Figure 4.58), what would you predict for the period in seconds? Explain briefly.

It was found that a 20 g mass hanging from a particular spring had an oscillation period of 1.2 s. (a) When two 20 g masses are hung from this spring, what would you predict for the period in seconds? Explain briefly.

A block with mass $m=10\ {\rm{kg}}$ is attached to a spring and oscillates on a frictionless surface. What is the period if the block's mass is quadrupled?

Which of the following is NOT a function of proteins?

A. store and transmit genetic information

B. help to fight disease

C. control the rate of reactions

D. move substances into or out of cells

What are the directions of the forces acting on the fan and on the sail due to these changes in momentum?

Resolve each force acting on the post into its $x$ and $y$ components.

To reach space, a rocket must overcome the force of gravity acting on it. Rocket engines burn fuel to provide thrust, or an upward force. Identify the forces acting on a rocket before liftoff and compare these forces to the ones acting on the rocket as it begins to lift off. Explain how the rocket is able to leave Earth and why the rocket continues to move upward after thrust has finished.

Find the magnitude and direction of the electrostatic force acting on the electron in the given figure.

How would the gravitational field at Earth’s surface be affected if Earth shrank in size without any change in mass? What would be its relative strength at the new surface if Earth shrank to half size? To one-tenth size?

During the final stages of descent, a sky diver with an open parachute approaches the ground with a constant velocity. There is no wind to blow him from side to side. Which one of the following statements is true? (a) The sky diver is not in equilibrium. (b) The force of gravity is the only force acting on the sky diver, so that he is in equilibrium. (c) The sky diver is in equilibrium because no forces are acting on him. (d) The sky diver is in equilibrium because two forces act on him, the downward-acting force of gravity and the upward-acting force of the parachute.

What are the magnitude and direction of the net force acting on the child?

If an object is at rest, what can you say about the forces acting on it?