Physics 8 Comp Mock Exam

What force is required to stretch a spring by 50 cm when the spring constant is 100N/m?

• 5000N

• 500N

• 50N

• 5N

A 0.5 kg soccer ball flies through the air after being kicked. When the ball is 3 m  above the ground, it has a velocity of 12 m/s. What is the total mechanical energy of the soccer ball?

• 50.7J

• 36J

• 230.7J

• 112.8J

An upward force is applied to lift a 20kg bag to a height of 5m at a constant speed. What is the work done on the bag?

• 500J

• 450J

• 100J

• 980J

What is the momentum of a 3 kg bird when it is flying at a height of 30 m above the ground with a speed of 10 m/s?

A 12-V battery is connected to three resistors with values of 3 Ω, 4 Ω, and 5 Ω, as shown below.  The equivalent resistance of the circuit is ____.

• 3Ω

• 5Ω

• 12Ω

• 60Ω

When a light ray passes from a medium with a high refractive index into a medium with a low refractive index, its path is

• bent away from the normal

• bent toward the normal

• parallel to the normal

• not bent

A voltage of 120 V across a light bulb results in a current of 15 Amperes. What is the resistance of the bulb?

• 4Ω

• 12Ω

• 6Ω

• 8Ω

Which of the following has the highest gravitational potential energy?

• A 1 kg book sitting on a high bookshelf

• A 1 kg book halfway down when falling off a high bookshelf

• A 1 kg book sitting on the floor

• A 1 kg book being pushed horizontally across the floor

A doctor lifts an instrument that weighs 167 N with a constant velocity of 6m/s.  How much force does she apply to lift it?

• Less than 167 N

• Exactly 167 N

• More than 167 N

• Exactly 1,636.6 N

• 58.5m

• 49.5m

• 24m

• 31.5m