Newton's 1st Law
A ball rolls across a table and falls off. What force causes the direction the ball is moving to change?
Gravity
What does the "a" stand for in the equation F = ma
Acceleration
According to Newton's 3rd Law, what does every action produce?
An equal and opposite reaction.
A force that always acts against a moving object.
Friction
For an object at rest, are the forces acting on it balanced or unbalanced?
balanced
How does a parachute slow down a skydiver's motion?
Increases air resistance.
If the force being applied to an object is increased, what happens to the object's acceleration?
It increases by the same amount.
To get out of a chair, you press down on the floor, what happens as a result of this?
The floor pushes against your feet with an equal force.
Not a force, but the tendency for an object at rest to stay at rest.
Inertia
It is not moving.
According to Newton's 1st law, what is necessary for an object at rest to begin moving?
A force.
A toy car is set into motion with a certain amount of force. If the same amount of force is used to set into motion an car is 3x more massive, how will the 2nd car's acceleration compare to the 1st?
The second car will have 1/3 of the acceleration of the first car.
A basketball bounces off of a backboard. Both objects applied an equal force on each other, so why might we not notice the movement of the backboard?
The ball is less massive so it has less inertia and its momentum is more easily changed.
A force that aids your motion when you are going downhill.
Gravity
A soccer player kicks a soccer ball, applying a force toward the south. In what direction does the ball move?
south
According to Newton's 1st law what is necessary to keep a moving object moving?
Inertia (or momentum)
Two objects with different masses are put into motion with the same amount of force. Which object will experience the most acceleration?
The less massive object
Why would pushing back on the water with an oar cause you to move forward?
The water pushes the oar with an equal force.
Not a force, but a change in velocity.
Acceleration
Three runners complete a 40-yard dash. Jim runs in 4.65 sec., George runs in 4.37, and Charlie runs in 4.82 sec. Who won the race?
George
A 1 kg, a 3 kg, and a 5 kg ball are set into motion with the same amount of force. Which ball will travel fartherst?
1 kg
A motor cycle, a dump truck, and a small car are traveling on the highway at the same speed. Which vehicle will require the most force to stop?
Dump truck
For a ball to bounce, the force applied by the floor has to be greater than the force of gravity. If you want the ball to bounce higher what must you do to the amount of force you use to throw the ball down?
Increase the downward force
Not a force, but an object's speed taken together with its direction of travel.
velocity
Remaining constant