Formulas
Displacement & Velocity
Acceleration and Free Fall
Forces
Momentum and Impulse
Conservation of Momentum
100
The formula for displacement.
∆d = y_f-y_i
100
You walk 40 ft around the perimeter of the room and end up 5 ft from where you started. Which measurement is the displacement?
5 ft
100
Does acceleration occur in this situation?
A car drives at 10 m/s in a circle.
Yes, because the car changed direction.
100
A person pushes their phone across a table. What forces act on the phone?
Applied force, friction, gravity, and normal force
100
Find the momentum of a 6 kg object that has a velocity of 25 m/s.
p = 150 kg m/s
100
Two cars collide and bounce off each other. What kind of collision occurs?
Elastic
200
The formula for velocity.
v = (∆d)/(∆t)
200
Your car's odometer measures that you drove 3 miles around the city. What is this measurement?
Distance
200
Does acceleration occur in this position graph?
No, because the object moves at constant velocity.
200
How much force would we have to add to put this object into equilibrium?
We would add 23 N to the right.
200
How do we achieve the largest possible impulse?
Apply the largest possible force for the longest possible period of time.
200
A person throws their pencil at another person. What kind of collision occurs?
Inelastic (Explosion)
300
The formula for acceleration.
a = (∆v)/(∆t)
300
What is your velocity if you are displaced by 10 m in 4 s?
2.5 m/s
300
A person increases their velocity by 12 m/s in 3 s. What is their acceleration?
4 m/s2
300
Newton's 1st Law says:
Objects maintain their motion in a straight line at constant velocity until they experience a net force. When they experience a net force they will accelerate.
300
How much force does a car experience if its momentum changes by 150 kg m/s in 0.17 s?
882.35 N
300
A sticky toy is thrown at a chair and sticks to it. What kind of collision occurs?
Inelastic (Stick)
400
The kinematics formula for ∆d.
∆d = 0.5at^2
400
What is the displacement?
8 m
400
Objects experience gravitational acceleration when they are in ____________.
Free Fall
400
Newton's 1st Law tells us that this object will:
Accelerate to the left.
400
How does changing the time that the force is applied for affect an object's change in momentum?
The longer the force is applied, the more the object's momentum will change.
400
In physics, to "conserve" something means that it...
stays the same!
500
The kinematics formula for final velocity.
v_f = v_i+at
500
Velocity is the ______ of the line on a position graph.
Slope
500
g on Earth is:
9.81 m/s2
500
Newton's 2nd Law tells us:
How much something accelerates when it experiences a net force:
SigmaF = ma
500
How does changing the collision time affect the force an object experiences when the change in momentum is kept the same?
Increasing the collision time decreases the force on the object.
500
A car with a momentum of 20 kg m/s hits another car with a momentum of 4 kg m/s and bounces. After the collision the first car has a momentum of -6 kg m/s. What is the momentum of the second car after the collision?
30 kg m/s
600
The formulas for impulse.
F∆t=∆p
F∆t = m∆v
600
The velocity from 5 s to 7 s is:
15 cm/s
600
Your pencil falls off a 2m tall table. How long does it take to fall?
0.63 s
600
Calculate the net force acting on a 6 kg object that experiences an acceleration of 21 m/s2.
SigmaF = 126 N
600
Why does a shoe with a hard sole hurt your feet but a shoe with memory foam does not?
The memory foam increases the collision time between your foot and the ground, causing the force to decrease.
600
Two objects collide and bounce off each other. Object 1 has a mass of 8 kg and moves at 4 m/s before the collision. Object 2 has a mass of 10 kg and moves at 2 m/s before the collision. After the collision Object 1 moves at -10 m/s. Find the velocity of object 2 after the collision.
13.2 m/s
700
The formula for momentum.
p=mv
700
What would the graph of something moving backward at constant velocity look like?
700
Your pencil falls off a 2m tall table. How fast is it moving just before it hits the ground?
6.18 m/s
700
Calculate the acceleration of this object:
3 m/s2 to the right
700
Why do runners sometimes prefer running on an asphalt road instead of a cement sidewalk?
The asphalt is slightly more flexible than cement and increases the collision time between their feet and the ground. This causes the force experienced by their feet to decrease.
700
A firework explodes into two pieces. Why won't the two pieces ever move in the same direction?
The momentum of both pieces have to add together to be 0 kg m/s. One has to be positive and one has to be negative.