Newton's Laws
An object will remain at rest unless....
acted upon by an unbalanced force.
What happens to an object if no net force acts on it?
remains at rest or continues moving at the same velocity.
How does increasing the distance between two objects affect gravity?
Gravity decreases as distance increases
A swimmer pushes water backward, what happens next?
The swimmer moves forward
If a 10 kg object experiences a 40 N force, what is its acceleration?
4 m/s2
Newton's first law of motion
If two objects experience the same force, which accelerates more?
The object with less mass
What is the main force opposing motion?
Friction
What happens to a skateboard when you jump off it?
The skateboard moves backward
A 1500 kg car accelerates at 4 m/s2. What force is acting on it?
6000 N
Newton's second law states that acceleration depends on...
force and mass
A 20 N force is applied to a 5 kg object. What is its acceleration?
4m/s2
Which surface would create the most friction: tile floor, glass, sandpaper
sandpaper
How can engineers reduce friction in high-speed trains?
reduce air resistance or smooth surfaces between rails & wheels
A 2 kg ball is moving 6 m/s. What is its momentum?
12 kgxm/s
Which law explains rocket launches?
What force pulls objects downward during free fall?
Gravity
What happens to friction when surfaces become smoother?
Friction decreases
Why do passengers lurch forward when a car suddenly stops?
Due to inertia
A 1000 kg car moving at 15 m/s collides with a 900 kg stationary car. If they stick together after the collision, what is their final velocity?
7.90 m/s
What is the reaction force when a bird flaps its wings downward?
The air pushes the bird upward
If a sled is pulled with 120 N and accelerates at 2 m/s2, what is its mass?
40 kg
List the 4 types of friction
rolling, sliding, static, fluid
What are the three types of orbit?
Geostationary, polar, and elliptical
A 3 kg ball moving at 8 m/s collides elastically with a 2 kg ball at rest. After the collision, the 3 kg ball comes to a stop. What is the velocity of the 2 kg ball?
12 m/s