True or false: km/s is an acceptable answer if you are asked to give your answer in SI units
False, km is not an SI unit, you must convert to meters
100
On a distance-versus-time graph, a speed of zero would appear as a _________________ line.
a) horizontal
b) vertical
c) sloped
horizontal
100
In projectile motion (assuming no air resistance), the velocity in the x direction is:
a)constant
b)not constant
c)always in the negative direction
d)always in the positive direction
Explain
Constant because no forces are acting in the x direction (assuming no air resistance)
100
What does Newton's first law state about the sum of the forces acting on a stationary object?
The sum of forces is equal to zero
100
The kinetic friction force always points in the _____ direction that the object is moving.
opposite
200
Sam is throwing darts and aiming for a bullseye, she manages to hit the green stripe on the 8 five times in a row instead. This is an example of:
a) accuracy
b) precision
c) both
d) neither
Explain
Precision but not accuracy
200
A ball is thrown vertically upward and then comes back down. During the ball's flight up and down, it's acceleration vector is:
a)always positive
b)always negative
c) first positive, then negative
d)first negative, the positive
Explain
Always negative because the acceleration is due to gravity in the downward direction the whole time
200
In projectile motion, the acceleration in the y direction is:
a) constant
b) not constant
c) always in the positive direction
d) always in the negative direction
(Hint: there are two correct answers)
Explain why you chose your answers
Constant and in the negative direction because the acceleration is due to the force of gravity
200
Newton's 2nd Law states that ____ is equal to mass times acceleration.
The sum of the forces
200
The friction force always depends on the normal force acting on the object and...
the coefficient of friction
300
What is the equation for rate?
rate=amount/time
300
A car travels from x=5.0 m to x=-22 m in 10.0 s. What is the car's velocity?
-2.7 m/s
300
True or false: When you draw a free-body diagram, you must include acceleration as a force acting on the object.
Explain
Acceleration is not a force. You must only include forces acting on the object in your free body diagram. You can write the acceleration off to the side.
300
The equal and opposite reaction pairs that are described in Newton's 3rd Law must act on:
a) The same object
b) 2 different objects
Explain your answer
2 different objects
300
True or False: Kinetic friction is always greater than static friction.
Explain
False
400
Ax is the _____ of vector A
a) magnitude
b) x-component
c) direction
d) size
e) displacement
x component
400
You throw a ball straight into the air. At the highest point the ball reaches, the velocity and acceleration are:
a) greater than 0 and negative
b) 0 and positive
c) 0 and negative
d) greater than 0 and positive
0 and negative
400
List the seven variables involved in a projectile motion problem
delta x, velocity in x-direction, time, acceleration in y direction, initial velocity in the y direction, final velocity in the y direction, and delta y.
400
A satellite is moving at a constant velocity through space, what can we say about the net force acting on the satellite?
Explain
The net force is 0 because acceleration is 0
400
Steve is pushing a box across the floor while Bob is trying to stop the box by pushing in the opposite direction. There is friction between the box and the floor. If the box is moving at a constant speed, then the magnitude of Steve's pushing force is:
a) greater than the magnitude of Bob's force
b) equal to the magnitude of Bob's force
c) less than the magnitude of Bob's force
d) the question can't be answered without knowing how large the friction force is
Explain