Newton's first law
What is another name for Newton's first law?
What is the law of inertia?
If a 5 kg object accelerates at 3 m/s², what is the net force acting on it?
What is 15 N (Newtons)?
A book rests on a table. The table pushes up on the book with 20 N. How much force does the book exert on the table?
What is 20 N downward?
A hockey puck slides across ice with no friction. Will it eventually stop? Why or why not?
What is no? It will continue moving at constant velocity because there's no unbalanced force.
What does newtons first law state?
•an object will move at a constant velocity until a net force acts on it.
–An object in motion will stay in motion unless a force acts on it.
–An object at rest will stay at rest unless a force acts on it.
A car suddenly stops. A passenger lurches forward. Explain what happens using Newton's 1st Law.
What is the passenger's body continues moving forward due to inertia because the car stopped but the passenger didn't experience a force to stop them immediately?
Two identical cars experience the same net force. Car A has a mass of 1,000 kg and Car B has a mass of 2,000 kg. Which accelerates more?
What is Car A?
A swimmer pushes backward on the water. What happens as a result?
What is the water pushes the swimmer forward?
A 10 kg box is pushed with a force of 50 N. If friction exerts 20 N of force opposing the motion, what is the acceleration?
What is 3 m/s²?
What does Newton second law state?
•A net force acting on an object causes the object to accelerate in the direction of the net force.
Why do astronauts float inside a spacecraft in orbit?
What is there is no net force acting on them, so they continue moving in a straight line (which happens to be circular around Earth)?
A net force of 100 N is applied to an object, causing it to accelerate at 5 m/s². What is the object's mass?
What is 20 kg?
A rocket launches into space by expelling hot gases downward. Explain the action-reaction pair.
What is the rocket pushes gases down, and the gases push the rocket up?
Compare the acceleration of a bowling ball and a tennis ball if you apply the same force to both.
What is the tennis ball accelerates faster because it has less mass?
What does Newton third law state?
•every action has an equal and opposite reaction.
A seatbelt prevents injury during a car crash. Explain using Newton's 1st Law.
What is the seatbelt provides a force to stop the passenger's forward motion, overcoming their inertia?
A 1,500 kg car accelerates from rest to 25 m/s in 8 seconds. What is the net force acting on the car?
What is 4,687.5 N (or approximately 4,700 N)?
A baseball player hits a ball with a bat. The bat exerts a 4,000 N force on the ball. According to Newton's 3rd Law, what force does the ball exert on the bat, and in which direction?
What is 4,000 N in the opposite direction (backward)?
An object accelerates at 2 m/s² when a 60 N net force is applied. What happens to the acceleration if the net force is tripled to 180 N?
What is it triples to 6 m/s²?
What is the Law of Universal Gravitation
•Any two masses exert an attractive force on each other.
Explain why a passenger in a car feels pushed to the side when the car turns a corner at constant speed.
What is the passenger's inertia causes them to continue in a straight line while the car curves, so they slide toward the outside of the turn?
Two forces act on a 4 kg object: 50 N forward and 20 N backward. What is the object's acceleration?
What is 7.5 m/s²?
A person stands on the ground. The Earth exerts an upward normal force on the person. What is the reaction force?
What is the person exerts a downward force on the Earth?
A 1,200 kg car experiences a friction force of 3,000 N while accelerating. If the engine provides 7,500 N of force, what is the car's acceleration?
What is 3.75 m/s²?
Law of Conservation of Momentum
momentum is never created or destroyed in a collision, it is only transferred.