Unit 1 Kinematics
What does the slope of a Position vs. Time graph represent?
Velocity
A car sits at rest in a driveway. What is the net force acting on the car?
0 N.
A tennis ball at the peak of its motion has what type(s) of energy?
Ug (gravitational potential)
In circular motion, what direction is considered positive?
Towards the center of the circle
What variable is used to show change in angular position?
Delta theta
If an object has a velocity of -3 m/s, what is its speed? (units must be correct for points).
3 m/s
A block of mass 2M and a block of mass M are each pushed with an applied force F. Which has a greater acceleration (or are they equal)?
Block with mass M
Give an example of a force that does negative work.
Friction, air resistance, a person pushing backwards (any opposing force)
Describe the direction of the velocity vector for an object moving in circular motion.
Tangential
A force of 20 N is applied to push open a door with a width of 1.5 m. What is the torque exerted on the door? (units must be correct for the point).
30 Nm
What does the area under a Velocity vs. Time graph represent?
Displacement
A baseball player swings and hits a ball (mass M) with his bat (mass 2M). The ball experiences a positive force F. What is the force experienced by the bat? (direction and magnitude).
-F
Car 1 (mass = m) moves to the right. Car 2 (mass = 2m) moves to the left. They approach each other with equal speed. They stick together after the collision. What direction do they move after the collision?
Left
A roller coaster car is at the top of its highest hill about to move downwards. Write an expression to represent the net force.
Fg - Fn
What two factors matter for rotational kinetic energy of an object? (must get both correct for points).
Rotational inertia and angular velocity.
What is the acceleration of a projectile in the horizontal direction and vertical direction? (must get both correct and units correct for points).
Horizontal: 0 m/s2
Vertical: -9.8 m/s2
A block (with mass m) is at rest on an inclined plane (with incline theta). What is an expression for the x-direction component of gravity for the block?
m*g*sin(theta)
If an object doubles it velocity, how does its kinetic energy change?
4x greater
What two factors impact the gravitational attraction force between objects? (must get both correct for points).
Distance between objects (r)
Mass of objects (m)
A rotating plate (radius = 2 m) is initially at rest. A force of 100 N is applied to the outer edge for 5 seconds. What is the angular impulse? (units must be correct for the point).
100 Nms
A ball is dropped from the top of a ladder with height H. What is the expression for the time it takes to hit the ground?
SqRt(2H/g)
Three blocks (all identical with mass M) are horizontally lined up. A person pushes on the left block with a force F. What is the acceleration of the system of 3 blocks?
F/(3M)
For an inelastic collision, is momentum conserved? Is energy conserved? (must get both right for the points).
Momentum YES
Energy NO
Two objects have a gravitational force between them of F. Then the distance between them triples. What is the new force of gravitational attraction, in terms of F.
F/9
What two factors impact the rotational inertia of a hollow sphere? (must get both correct for points).
Mass & Radius