Physics Exam 2

Which of the following statements is true? A satellite's velocity and orbital radius are independent of each other. A satellite's motion is independent of its mass. A geosynchronous satellite has a period of approximately 28 days. The net force acting on a satellite is zero.

A satellite's motion is independent of its mass.

What can you say about the force of gravity, Fg acting on the stone and the feather?

Fg is greater on the stone

People could not walk without friction. Which friction are we talking about here, kinetic friction or static friction?

Static

Which of the following statements is true? The Sun is located at one of the foci of the planets' elliptical orbits. The Sun is located at the center of the of the planets' circular orbits. The path of the planets around the Sun is circular in shape.

The Sun is located at one of the foci of the planets' elliptical orbits.

A hypothetical planet has a mass one-third of and a radius three times that of Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity on Earth?

The acceleration due to gravity is g/27

An object moves in a circular path at a constant speed. What is the relationship between the directions of the object's velocity and acceleration vectors?

The velocity and acceleration vectors are perpendicular.

Why does a satellite in a circular orbit travel at a constant speed?

There is no component of force acting along the direction of motion of the satellite.

Is the moon accelerating as it orbits the Earth?

Yes. It is accelerating even though its speed is constant.

In general, how does the coefficient of static friction compare to the coefficient of kinetic friction for the same two materials? The coefficient of static friction

can be greater than or equal to the coefficient of kinetic friction.

You drive your dad's car too fast around a curve and the car starts to skid. What is the correct description of this situation?

friction between tires and road is not strong enough to keep car in a circle

Earth's orbit around the Sun is slightly elliptical. Thus, Earth actually gets closer to the Sun during part of the year. What happens to Earth's orbital speed when it is closer to the Sun? Earth's orbital speed is

greater when it is closer to the Sun than when it is farther from the Sun

An object moves in a circular path at a constant speed. What is the direction of the net force acting on the object?

is directed toward the center of the circular path.

What can you say about the acceleration due to gravity acting on the stone and the feather?

it is equal on both always

A block sits at rest on a rough straight incline. The box doesn't slide down the incline because static friction keeps it in place. The friction force from the incline on the block is

less than the force of gravity.

A pilot executes a vertical dive then a semi-circular arc until the plane is going straight up. Just as the plane is at its lowest point, the force from the seat on the pilot is

more than mg, and pointing up.

A planet is discovered orbiting around a star in the galaxy Andromeda at the same distance from the star as Earth is from the Sun. If that star has four times the mass of our Sun, how does the orbital period of the planet compare to Earth's orbital period? The planet's orbital period will be

one-half Earth's orbital period.

If you weigh yourself at the equator of Earth, would you get a bigger, smaller, or similar value than if you weigh yourself at one of the poles?

smaller value

According to Newton's Law of Gravity, if you were lifted so that you were 10 times further from the center of the Earth than you are now

your weight would be 100 times smaller.

A crate is moving to the right on a conveyor belt without slipping. The conveyor belt maintains a constant speed. The force of friction on the crate is

zero