Newton's 1st Law Practice

When forces are ​ (a)   ​ in opposite directions they produce a(n) ​ (b)   net force.

• uneven
• unbalanced
• moving
• balanced
• increasing

Velocity only changes when ​ (a)   is applied.

• unbalanced force
• balanced force
• inertia
• power

Match the following

• balanced forces

• causes velocity to change

• inertia

• creates a net force of zero

• velocity

• resists changing velocity

• acceleration

• the speed and direction of an object

• force

• a way to measure change in velocity

Izabel is pedaling a bicycle with a force of 200n east. The wheels have a friction force of 150n west. The air resistance around her creates a force of 50n west. Given these conditions, predict what will happen.​ ​ ​ (a)  

• the bicycle will keep the same velocity
• the bicycle will speed up going east
• the bicycle will slow down but still go east
• the bicycle will stop moving
• the bicycle will change directions and go west

Jermaine has a model rocket. The model rocket can create an upward force of 300n. The force of gravity gives the rocket a weight of 100n. The rocket has enough fuel to last 10s. Predict the motion of the rocket.

• The velocity will increase upward for 10 seconds, then the velocity will decrease until it changes direction, then increase in a downward direction

• The rocket will have a constant upward velocity for 10s, then change direction and increase downward velocity.

• The rocket will increase velocity upward for 10s then slow down and change direction, falling at a constant velocity

• The rocket will have a constant upward velocity, then slow down, then fall with a constant downward velocity.

The force diagram here shows 4 forces acting on an object. Based on these forces, how will the object's motion be affected?

• it will accelerate upward

• it will not move

• it will accelerate upward, and either left or right.

• it will accelerate downward

A spaceship is traveling 1500 m/s. It has thrusters to provide a forward push and braking thrusters to push backwards. If none of the thrusters are on, what will happen to the spaceship's motion?

• it will continue moving forward at 1500 m/s

• it will slow down over time and stop

• it will speed up moving foward.

• it will change direction

A spaceship is traveling 1500 m/s. It has thrusters to provide a forward push and braking thrusters to push backwards. If the forward thrusters are turned on low power, what will happen to the spaceship's motion?

• it will continue moving forward at 1500 m/s

• it will slow down over time and stop

• it will speed up in the forward direction

• it will change direction

A spaceship is traveling 1500 m/s. It has thrusters to provide a forward push and braking thrusters to push backwards. If the braking thrusters are turned on low power, what will happen to the spaceship's motion?

• it will continue moving forward at 1500 m/s

• it will slow down over time and stop

• it will speed up in the forward direction

• it will change direction

Use the terms velocity, acceleration, force, and inertia to explain Newton's 1st Law of Motion.