AP Physics Misconceptions

A ball is thrown straight up in the air. When the ball reaches its highest point, which of the following is true?

• It is in equilibrium.

• It has zero acceleration.

• C It has maximum momentum.

• It has maximum kinetic energy

• None of the above

Tags

NGSS.HS-PS2-1

A box is given a sudden push up a ramp. Friction between the box and the ramp is not negligible. Which of the following diagrams best represents the directions of the actual forces acting on the box as it moves upward after the push?

• 
• 
• 
• 
• 

Tags

NGSS.HS-PS2-1

A planet of mass m orbits a star of mass M, where m<<M. The orbit is circular, its radius is r, and

its period is T. True statements about the planet’s orbit include which of the following?

I. The orbital speed equals 2πr / T

II. The gravitational force equals GMm / r2

III. If the orbital radius r were greater, T would also be greater.

• I only

• II only

• I and III only

• II and III only

• I, II, and III

Tags

NGSS.HS-ESS1-4

NGSS.HS-PS2-4

While traveling in its elliptical orbit around the Sun, Mars gains speed during the part of the orbit where it is getting closer to the Sun. Which of the following can be used to explain this gain in speed?

• As Mars gets closer to the Sun, the Mars–Sun system loses potential energy and Mars gains kinetic energy.

• A component of the gravitational force exerted on Mars is perpendicular to the direction of motion, causing an acceleration and hence a gain in speed along that direction.

• The torque exerted on Mars by the Sun during this segment of the orbit increases the Mars–Sun system’s angular momentum.

• The centripetal force exerted on Mars is greater than the gravitational force during this segment of the orbit, causing Mars to gain speed as it gets closer to the Sun.

Tags

NGSS.HS-ESS1-4

NGSS.HS-PS2-4

A rock of mass m is thrown horizontally off a building from a height h, as shown above. The speed of the rock as it leaves the thrower's hand at the edge of the building is v.

What is the kinetic energy of the rock just before it hits the ground?

• mgh

Tags

NGSS.HS-PS3-1

What is the kinetic energy of a satellite of mass in that orbits the Earth, of mass M, in a circular orbit of radius R ?

• zero

Tags

NGSS.HS-ESS1-4

NGSS.HS-PS2-4

An object is moving in the positive x-direction while a net force directed along the x-axis is exerted on the object. The figure above shows the force as a function of position. What is the net work done on the object over the distance shown?

Tags

NGSS.HS-PS2-1

NGSS.HS-PS3-2

Three objects can only move along a straight, level path. The graphs below show the position d of each of the objects plotted as a function of time t.

The sum of the forces on the object is zero in which of the cases?

• II only

• III only

• I and II only

• I and III only

• I, II, and III

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

An object is thrown with an initial speed v near the surface of Earth. Assume that air resistance is negligible and the gravitational field is constant.

If the object is thrown vertically upward, the direction and magnitude of its acceleration while it is in the air is

• upward and decreasing

• upward and constant

• downward and decreasing

• downward and increasing

• downward and constant

Tags

NGSS.HS-PS2-1

An object has a weight W when it is on the surface of a planet of radius R. What will be the gravitational force on the object after it has been moved to a distance of 4R from the center of the planet?

• 16W

• 4W

• W

Tags

NGSS.HS-PS2-4