Exam III

Driving 65 mph. Traveling north along straight highway. What could you do to give car nonzero acceleration? -press brake pedal -turn steering wheel -either press the gas or brake pedal -either press gas or brake pedal or turn steering wheel

-either press gas or brake pedal or turn steering wheel

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 the same whether it is closer to the Sun or farther from the Sun. Earth's orbital speed is less when it is closer to the Sun than when it is farther from the Sun. Earth's orbital speed is greater when it is closer to the Sun than when it is farther from the Sun.

Earth's orbital speed is greater when it is closer to the Sun than when it is farther from the Sun.

Would it require less speed to launch a satellite a) toward the east or b) toward the west? Why?

In order to orbit, a satellite must reach an orbital speed relative to the center of the earth. Since the satellite is already moving eastward when launched (due to the rotation speed at the surface of the earth) it requires less additional speed (therefore less energy) to launch it east to get to final orbital speed

Which of the following statements are true? Check all that apply. The launch speed of a satellite determines the shape of its orbit around Earth. A geosynchronous satellite has a period of approximately 28 days. A satellite's velocity and orbital radius are independent of each other. A satellite's motion is independent of its mass.

The launch speed of a satellite determines the shape of its orbit around Earth. A satellite's motion is independent of its mass.

An object moves in a circular path at a constant speed. What is the direction of the net force acting on the object? The net force points in the same direction as the motion of the object. The net force is directed away from the center of the circular path. The net force is directed toward the center of the circular path. The net force points in the direction opposite to the motion of the object. The net force is zero because the object is moving with a constant speed.

The net force is directed toward the center of the circular path.

which are true The path of the planets around the Sun is elliptical in shape. The Sun is located at the center of the of the planets' circular orbits. The Sun is located at one of the foci of the planets' elliptical orbits. The path of the planets around the Sun is circular in shape.

The path of the planets around the Sun is elliptical in shape. The Sun is located at one of the foci of the planets' elliptical orbits.

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 twice Earth's orbital period. The planet's orbital period will be four times Earth's orbital period. The planet's orbital period will be equal to Earth's orbital period. The planet's orbital period will be one-fourth Earth's orbital period. The planet's orbital period will be one-half Earth's orbital period.

The planet's orbital period will be one-half Earth's orbital period.

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 vector points toward the center of the circular path. The acceleration is zero. The velocity and acceleration vectors are perpendicular. The velocity and acceleration vectors point in opposite directions. The velocity and acceleration vectors point in the same direction. The velocity vector points in a direction tangent to the circular path. The acceleration is zero

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. The net force acting on the satellite is zero. The gravitational force acting on the satellite is balanced by the centrifugal force acting on the satellite. There is a force acting opposite to the direction of the motion of the satellite.

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

A ball is lodged in a hole in the floor near the outside edge of a merry-go-round that is turning at constant speed. Which kinematic variable or variables change with time, assuming that the position is measured from an origin at the center of the merry-go-round? the position of the ball only the velocity of the ball only the acceleration of the ball only both the position and velocity of the ball the position and velocity and acceleration of the ball

the position and velocity and acceleration of the ball

You throw a ball. Air resistance on the ball is negligible. Which of the following functions change with time as the ball flies through the air? only the position of the ball only the velocity of the ball only the acceleration of the ball the position and velocity of the ball the position and the velocity and acceleration of the ball

the position and velocity of the ball