Which term identifies a scalar quantity?

• displacement

• time

• momentum

• velocity

Two 20.-newton forces act concurrently on an object. What angle between these forces will produce a resultant force with the greatest magnitude?

• 0°

• 45°

• 90°

• 180°

The centripetal force acting on the space shuttle as it orbits Earth is equal to the shuttle’s

• momentum

• inertia

• velocity

• weight

An 8.0-newton wooden block slides across a horizontal wooden floor at constant velocity. What is the magnitude of the force of kinetic friction between the block and the floor?

• 3.0 N

• 8.0 N

• 2.4 N

• 5.0 N

A particle could have a charge of

• 0.8×10^−19 C

• 1.2×10^−19 C

• 3.2×10^−19 C

• 4.1×10−19 C

A rock is thrown straight up into the air. At the highest point of the rock’s path, the magnitude of the net force acting on the rock is

• less than the magnitude of the rock’s weight, but greater than zero

• greater than the magnitude of the rock’s weight

• the same as the magnitude of the rock’s weight

• zero

An object accelerates uniformly from 3.0 meters per second east to 8.0 meters per second east in 2.0 seconds. What is the magnitude of the acceleration of the object?

• 2.5 m/s^2

• 5.0 m/s^2

• 5.5 m/s^2

• 3.0 m/s^2

An object accelerates uniformly from 3.0 meters per second east to 8.0 meters per second east in 2.0 seconds. What is the magnitude of the acceleration of the object?

• 2.5 m/s^2

• 5.0 m/s^2

• 5.5 m/s^2

• 3.0 m/s^2

As a box is pushed 30. meters across a horizontal floor by a constant horizontal force of 25 newtons, the kinetic energy of the box increases by 300. joules. How much total internal energy is produced during this process?

• 150 J

• 450 J

• 250 J

• 750 J

A baseball is thrown at an angle of 40.0° above the horizontal. The horizontal component of the baseball’s initial velocity is 12.0 meters per second. What is the magnitude of the ball’s initial velocity?

• 7.71 m/s

• 9.20 m/s

• 15.7 m/s

• 18.7 m/s

A number of 1.0-newton horizontal forces are exerted on a block on a frictionless, horizontal surface. Which top-view diagram shows the forces producing the greatest magnitude of acceleration of the block?

A car uses its brakes to stop on a level road. During this process, there must be a conversion of kinetic energy into

• light energy

• nuclear energy

• internal energy

• gravitational potential energy

When a teacher shines light on a photocell attached to a fan, the blades of the fan turn. The brighter the light shone on the photocell, the faster the blades turn. Which energy conversion is illustrated by this demonstration?

• light → thermal → mechanical

• light → nuclear → thermal

• light → electrical → mechanical

• light → mechanical → chemical

Two electrons are separated by a distance of 3.00 × 10−6 meter. What are the magnitude and direction of the electrostatic forces each exerts on the other?

• 2.56 × 10^−17 N away from each other

• 2.56 × 10^−17 N towards each other

• 7.67 × 10^−23 N away from each other

• 7.67 × 10^−23 N towards each other

Two electrons are separated by a distance of 3.00 × 10−6 meter. What are the magnitude and direction of the electrostatic forces each exerts on the other?

• 2.56 × 10^−17 N away from each other

• 2.56 × 10^−17 N towards each other

• 7.67 × 10^−23 N away from each other

• 7.67 × 10^−23 N towards each other

Moving a length of copper wire through a magnetic field may cause the wire to have a

• potential difference across it

• lower temperature

• lower resistivity

• higher resistance

A sound wave traveling eastward through air causes the air molecules to

• vibrate east and west

• vibrate north and west

• move eastward, only

• move northward, only

Which particles are not affected by the strong force?

• hadrons

• protons

• electrons

• neutrons

A photon is emitted as the electron in a hydrogen atom drops from the n = 5 energy level directly to the n = 3 energy level. What is the energy of the emitted photon?

• 0.85 eV

• 0.97 eV

• 1.05 eV

• 2.01 eV

Which graph represents the relationship between the magnitude of the gravitational force exerted by Earth on a spacecraft and the distance between the center of the spacecraft and center of Earth? [Assume constant mass for the spacecraft.]

A ray of light ( f = 5.09 × 1014 Hz) travels through various substances. Which graph best represents the relationship between the absolute index of refraction of these substances and the corresponding speed of light in these substances?

A 4.0-kilogram object is accelerated at 3.0 meters per second^2 north by an unbalanced force. The same unbalanced force acting on a 2.0-kilogram object will accelerate this object toward the north at

• 12 m/s^2

• 6 m/s^2

• 3 m/s^2

• 1.5 m/s^2

When two point charges of magnitude q1 and q2 are separated by a distance, r, the magnitude of the electrostatic force between them is F. What would be the magnitude of the electrostatic force between point charges 2q1 and 4q2 when separated by a distance of 2r?

• 2F

• F

• 16F

• 4F

In a process called pair production, an energetic gamma ray is converted into an electron and a positron. It is not possible for a gamma ray to be converted into two electrons because

• charge must be conserved

• momentum must be conserved

• mass-energy must be conserved

• baryon number must be conserved

Which particle would produce a magnetic field?

• a neutral particle moving in a straight line

• a neutral particle moving in a circle

• a stationary charged particle

• a moving charged particle

Which diagram represents the electric field between two oppositely charged conducting spheres?

Which diagram represents the electric field between two oppositely charged conducting spheres?