Kinematics
What does a flat (horizontal) line on a position-time graph tell you?
The object is not moving.
Newton's 3rd Law says every action has... what?
An equal and opposite reaction.
What is momentum a product of?
Mass and velocity.
What is work in physics?
Applying a force over a distance or a change in total energy of a system
What does the slope of a position-time graph represent?
Velocity.
True or False: A negative velocity always means an object is slowing down.
False — it depends on direction and acceleration.
If a box moves at constant velocity, what can we say about the net force?
It’s zero.
What is impulse?
A change in momentum or a force applied over a period of time.
What kind of energy does a stretched spring have?
Elastic potential energy.
What does the slope of a velocity-time graph represent?
Acceleration.
What’s the difference between constant speed and constant velocity?
Constant velocity means both speed and direction are constant.
Jenny pushes a box with 50 N and it moves at constant velocity. What does this tell you about friction?
Friction is also 50 N — balanced forces.
True or False: Momentum is always conserved in a collision.
True — if no external forces act on the system.
Name two forms of mechanical energy.
Kinetic energy and potential energy.
How can you tell from a graph when an object changes direction?
Velocity crosses the time axis (goes from positive to negative or vice versa).
How can you find displacement from a velocity-time graph?
By calculating the area under the curve.
Give an example of an object moving right while the net force is left.
A car skidding to a stop after brakes are applied
If a truck and a small car collide and stick together, what happens to their final velocity?
They share the same final velocity — based on total momentum.
What does it mean when energy is conserved in a system?
Total energy stays the same, though it can change forms.
On a v-t graph, when is the object stopped?
When velocity = 0.
Elmer says "Negative acceleration means slowing down." Do you agree? Why or why not?
Disagree — it depends on direction. An object can speed up with negative acceleration if it’s moving in the negative direction.
A bug hits a windshield and splatters. Why doesn’t the bug "hit harder"?
Both exert equal forces — the bug’s small mass causes greater acceleration and damage.
What’s the difference between something that is constant vs. something that is conserved?
Constant means unchanging; conserved means total remains the same, even if parts change.
A ball compresses a spring and stops. What energy transformation occurred?
Kinetic → Elastic potential energy.
On a p-t graph, how can you tell that the object is accelerating?
When the graph is curved