Projectile Motion
The acceleration in this direction is zero.
The acceleration in this direction is zero.
The change in position
displacement
Energy is the ability to do what?
work
The force on one object by another object is _____ in magnitude but ______ in direction.
equal
opposite
Can the resultant of the addition of two parallel vectors be less than the magnitude of one of the individual vectors?
Yes, because it depends on the direction of the vectors.
The path of a projectile
trajectory
the unit for kinetic energy
Joules J
This variable decides how fast a toy car will be going when it reaches the bottom of a frictionless ramp.
The height
If one of the chares is doubled, the electrostatic force between it and another object _____ (increases or decreases) by how much?
Increases by twice as much
A baseball is hit high into the air and is caught easily by the shortstop. When the ball reached it maximum height, its speed was …
less than its initial speed
If a rock is thrown horizontally off a bridge, how much farther will it travel if it is thrown twice as fast?
Twice as far
a quantity that has magnitude and direction
a vector
Kinetic energy, measured in joules, is based on an object's (two variables)
mass and speed
DAILY DOUBLE
For an object to be accelerating, it must do one of three things. Name the three actions.
speed up
slow down
change direction
If a car is moving at a constant speed of 25 m/s on a straight road, what can be said about the net force acting on the car?
The net force must be equal to zero.
ΣF = ma
If zero acceleration, zero net force.
Which tennis ball would hit the ground first, a tennis ball shot horizontally out of a ball machine with a speed of 34 m/s or a ball dropped from the same height?
Neither - both hit at the same time
DAILY DOUBLE
Kinetic energy is the _________. What are two types of energy that represent kinetic energy?
Kinetic energy is the energy of motion. Examples are mechanical, electrical, light, sound, and thermal.
What is the potential energy of a 200 kg object, 50 meters above a reference point?
98,100 J
How will the electrostatic force between two charges change if each charge doubles and the distance of separation decrease by ½?
16
DAILY DOUBLE
If a passanger sitting on a train moving 20 m/s [E] throws a ball straight up into the air inside the train car, where will the ball land relative to that person, AND to an individual standing stationary outside the train at a station, what would the ball’s motion look like?
The ball will land back in the passenger’s hand
and
to a stationary observer outside the train, the ball’s motion will look like an arch or parabola.
If a ball is dropped from a 10 m high bridge, it is in the air for how long?
1.4 seconds
For every force, there is a force equal in magnitude but opposite in direction
Newton’s 3rd Law
DAILY DOUBLE
If a 800 kg roller coaster car at rest atop of a hill has 196,200 J of potential energy, how high is the hill AND how fast will it be going at the bottom of the hill? (assuming no friction)
Hill is 25 m high
and
Speed at bottom of the hill is 22 m/s
Can an object with zero acceleration be moving?
Yes
(constant velocity)
What two variables does the coefficient of friction depend?
The normal force and
the force of friction