3rd grade forces and motion

Example

On which surface would you slide furthest in your socks?

1. Smooth surfaces have less friction, so you slide further.
2. So the answer is: a polished wooden floor

Answer: a polished wooden floor

Example

Balanced forces: which statement is NOT true?

1. With balanced forces it can move at a steady speed.
2. So the answer is: If an object is moving, the forces on it cannot be balanced.

Answer: If an object is moving, the forces on it cannot be balanced.

Example

A cyclist pedals harder than the air and road push back. What happens?

1. Unbalanced forward force makes the bike speed up.
2. So the answer is: The bike speeds up.

Answer: The bike speeds up.

Example

In a tug of war, the Red team's pullers pull with 80 N, 120 N, 80 N, 110 N. What is the Red team's total pull?

1. 80 + 120 + 80 + 110 = 390
2. So the answer is: 390 N

Answer: 390 N

Example

A playground swing takes 3 seconds to swing forward and back once. The pattern repeats. How many complete swings will it make in 24 seconds?

1. 24 ÷ 3 = 8
2. So the answer is: 8

Answer: 8

Example

Is this a contact force or a non-contact force: kicking a ball?

1. The objects must touch for the force to act.
2. So the answer is: contact force

Answer: contact force