LOUDEN Gizmos: Force Fan Cart ASSIGNMENT

A fan cart with the fan set to High rolled across a floor. The cart's speeds are shown below. If the fan were set to Medium instead, what could the cart's speed be at 5 seconds?

• 31.0 cm/s

• 40.1 cm/s

• 10.9 cm/s

• 48.3 cm/s

Answer explanation

The fan speed affects the cart's velocity. Setting the fan to Medium would reduce the speed significantly compared to High. Among the options, 10.9 cm/s is the most plausible speed for Medium at 5 seconds.

Based on the speed data table, what is the speed at 5 seconds?

• 10.9 cm per second

• 31.0 cm per second

• 40.1 cm per second

• 48.3 cm per second

Force is needed:

• for a moving object to keep moving at the same speed and direction

• for a moving object to change its speed

• for a motionless object to remain still

• to prevent a moving object from turning

Answer explanation

Force is required to change the speed of a moving object, as per Newton's second law. An object in motion will maintain its speed and direction unless acted upon by an external force.

Rebecca puts her backpack on a fan cart and turns the fan on. She then measures the speed each second afterward. At 10 seconds the cart has a speed of 20 cm per second. How fast will the cart be moving at 12 seconds?

• 18 cm per second

• 20 cm per second

• 22 cm per second

• 24 cm per second

Answer explanation

The cart's speed increases by 2 cm per second each second. At 10 seconds, it is 20 cm/s. Therefore, at 11 seconds it will be 22 cm/s, and at 12 seconds it will be 24 cm/s, making the correct answer 24 cm per second.

A fan cart is moving forward on a frictionless surface. If you change the fan force from High to Low, what will occur?

• The cart will stop moving.

• The cart will slow down.

• The cart will keep moving at the same speed.

• The cart will continue to speed up, but not as quickly as before.

Answer explanation

When the fan force is reduced from High to Low, the cart will still experience a forward force, allowing it to continue speeding up, but at a reduced rate compared to before.

The speed-versus-time bar graph for a fan cart experiment is shown below. What could have happened?

• The track was frictionless, and the fan was changed from High to Low after 8 seconds.

• The track was frictionless, and the fan was changed from High to Off after 8 seconds.

• The track was wooden, and the fan was changed from High to Off after 8 seconds.

• The track was wooden, and the fan was changed from Off to Low after 8 seconds.

Answer explanation

The graph indicates a sudden drop in speed after 8 seconds, suggesting the fan was turned off. A frictionless track supports this, as there would be no resistance to slow the cart down.