Physics Spring Semester Exam

Two charged spheres are 16 cm apart. If the spheres are moved closer to each other so that they are 8 cm apart, how does the force between them change?

• The force will decrease by a factor of 2.

• The force will increase by a factor of 2.

• The force will decrease by a factor of 4.

• The force will increase by a factor of 4.

What does the law of conservation of momentum state?

• Total momentum before a collision is equal to the total momentum after the collision

• Total momentum before a collision is greater than the total momentum after the collision

• Total momentum before a collision is less than the total momentum after the collision

• Total momentum before a collision is unrelated to the total momentum after the collision

Which action makes use of a magnetic force?

• A person puts a bank card in an electronic reader to buy an item.

• A store clerk finds the price of an item by moving the item over a laser light.

• A parent measures a child's temperature by touching a thermometer to the child's head.

• A student measures the mass of a book using a spring scale.

A student makes a graph that shows the electric current through a resistor over time. Which of the following conclusions does the graph best support?

• The voltage across the resistor decreases until it becomes zero.

• The voltage across the resistor increases until it reaches a constant value.

• A fuse in the circuit blows after approximately 30 seconds.

• The resistance decreases as the voltage increases.

A car traveling on a level road initially has 440 kJ of mechanical energy. After the brakes are applied for a few seconds, the car has only 110 kJ of mechanical energy. What best accounts for the missing mechanical energy?

• Half the missing mechanical energy has been converted to heat energy, and the other half has been destroyed.

• Most of the missing mechanical energy has been converted to gravitational potential energy.

• Half the missing mechanical energy has been converted to kinetic energy, and the other half has been converted to potential energy.

• Most of the missing mechanical energy has been converted to heat energy through friction.

The velocity of a wave is primarily determined by

• the size of the oscillation

• the energy of the wave

• the period of oscillation

• the medium in which the wave travels (air, vacuum, water, etc.)

Which statement best explains the difference between light waves traveling through a vacuum and light waves traveling through a medium, such as water or air?

• Light waves traveling through a vacuum are transverse, but light waves traveling through a medium are longitudinal.

• Light waves traveling through a vacuum travel faster than light waves traveling through a medium.

• Light waves traveling through a vacuum have no mass, but light waves traveling through a medium have a mass greater than zero.

• Light waves traveling through a vacuum have a shorter wavelength than light waves traveling through a medium.

Which real-world scenario involves the practical application of impulse and momentum?

• Designing effective airbags in cars

• Painting a wall with a brush

• Watering plants in a garden

• Cooking a meal in the kitchen

Impulse can also be expressed as the change in __ of an object.

• Mass

• Velocity

• Momentum

• Force

What is the frequency of the wave?

• A. 2 Hz

• B. 0.5 Hz

• C. 0.25 Hz

• D. 4 Hz