3rd PT REVIEW in Science 6

In the field of engineering, transportation, and manufacturing, understanding the nature and impact of friction is crucial. Which of the following shows that friction could be harmful?

• holding a piece of paper

• tearing out of bicycle gears

• using breaks when stopping.

• writing on the board

A ball rolled after being kicked and slowed down until it stopped. Which of the following forces caused the ball to slow downed?

• electrical

• friction

• gravity

• magnetic

Why do you need to put rollers under the cabinets when you want to move them?

• to apply more force

• to minimize friction through the small surface of contact of the rollers

• to slow down the movement of the cabinet

• to stop the movement of the cabinet

Imagine you're driving down a city street and approach a red light. How are you going to stop your moving vehicle?

• Do nothing to increase the friction.

• Look at the brake pedal to increase friction.

• Press the brake pedal to increase friction.

• Release the brake pedal to increase friction.

Imagine an astronaut floating outside the International Space Station. They have a wrench in their hand. If they release the wrench, it doesn't float away. Instead, the wrench is pulled towards the Earth by gravity. How can you describe gravity in this scenario?

• A force that can be turned on and off

• A force that only affects objects on Earth

• A repulsive force between objects

• An attractive force between objects

Why do drivers drive their car slowly during rainy days?

• Drivers drive slowly because they are afraid of the rain.

• Drivers drive slowly because the road is wet so there is less friction.

• Drivers drive slowly because the road is wet so there is more friction.

• Drivers drive slowly because the windshield is blurred.

You're holding an apple. Unconsciously, you're exerting an upward force to keep it from falling. Why do objects fall to the ground?

• Because of the Earth's gravitational pull

• Because they are attracted to the center of the Earth by magnetic forces

• Because they are pushed by the air

• Due to a mysterious force that we don't understand

Imagine two magnets. When they are close together, the magnetic force is strong. As you move them further apart, the magnetic force weakens. According to the law of universal gravitation, how does the force of gravity between two objects change?

• Decreases with increasing distance

• Increases with increasing distance

• Is always constant

• Is not affected by distance

You are watching a basketball game. How does gravity affect the movement of a ball thrown upwards by the players to shoot?

• Gravity has no effect on the ball's movement.

• Gravity pulls the ball downwards, causing it to eventually fall back to the ground.

• Gravity pulls the ball upwards, making it go higher.

• Gravity pushes the ball sideways, changing its direction.

Imagine you're hiking up a steep mountain trail. Why is it difficult for us to go up in a mountain than go down?

• We are moving against gravity.

• We are moving towards gravity.

• We are pulled by the wind.

• We are releasing energy.