Momentum
Formula for momentum
p=mv
What is displacement?
The distance and direction of an object's change in position.
What makes up velocity?
Speed and Direction
A baseball of mass 0.145 kg is thrown with a velocity of 40 m/s. If the baseball hits a bat and comes to a complete stop, what is the change in momentum of the baseball?
5.8 kg*m/s
Momentum
A person walks 4 meters south and then 3 meters north. What is the displacement from the starting point?
1 meter south
What is the formula for velocity?
v=d/t
*Including direction
A cyclist travels 15 kilometers west in 30 minutes and then 20 kilometers east in 1 hour. Calculate the cyclist's overall displacement and average velocity for the entire trip.
23.3 km/h east
5 km east
An object’s momentum includes its _____.
Velocity and Mass
A dog runs 10 meters west, then 6 meters east. What is the dog's displacement?
4 meters west
A cyclist rides 30 miles west in 1.5 hours. Calculate the velocity of the cyclist in miles per hour.
20 mph west
Compare and contrast velocity and speed. How are they similar and how do they differ?
Velocity is speed and direction
Speed is the rate at which an object is moving (formula distance/time)
An object can have the same speed and different velocity.
What is the momentum a 70-kg dolphin swimming 11.4 m/s.
798 kg*m/s
A boat travels 30 kilometers in a straight line to a destination and returns directly to the starting point. What is the boat's displacement for the entire trip?
0 km
Displacement = Final position - initial position = 0 km
You are walking toward the back of a train that is moving forward with a constant velocity. The train’s velocity relative to the ground is 30 m/s forward. Your velocity relative to the train is 1.5 m/s backward. What is your velocity relative to the ground?
Velocity = 30 m/s - 1.5m/s = 28.5 m/s forward
A train travels north 120 kilometers in 2 hours and then 180 kilometers in 3 hours. What is the average velocity of the train for the entire journey?
60 km/h north
What is the momentum of a 7300-kg elephant walking 0.15 m/s
1095 kg*m/s
You are walking toward the back of a bus that is moving forward with a constant velocity. Describe your motion relative to the bus and relative to a point on the ground.
Relative to the bus, you move backward at your walking speed. Relative to the ground, you move in the same direction as the bus with a speed equal to the bus’s speed minus your walking speed (assuming that the bus moves faster than you walk).
A boat moves 60 kilometers upstream in 3 hours 15 minutes. What is the velocity of the boat in kilometers per hour?
*Round your answer to the nearest tenth
18.5 km/h upstream
Runner Distance Covered (km) Time (min)
Ling-Ling 12.5 42
LaToya 7.8 38
Bill 10.5 32
Jose 8.9 30
If all four runners have the same mass, who has the smallest momentum?
LaToya