Motion Described
Define reference point
An object that appears to stay in place.
Acceleration is the rate of change in _________ or _________ or both.
Speed or Direction
Define momentum.
The force that an object has due to its motion.
A force is just a ______ or _____.
Push or pull
Sliding, rolling, and fluid friction are all types of ____________.
Kinetic friction
What is the difference between qualitative and quantitative?
Qualitative has no numbers and quantitative uses numbers.
Explain the difference between elastic and inelastic collision.
Elastic collision occurs when objects collide so that kinetic energy and momentum are conserved. Inelastic collision only conserves momentum.
Explain the law of conservation of momentum.
Any time objects collide, the total amount of momentum stays the same.
If equal forces act in opposite directions, they are called ________.
balanced forces
Define static friction
The friction between two surfaces when they are not moving relative to each other.
During a bicycle ride, the cyclist takes 6s to cover the first 20 m. She then travels 30 m in 5s at constant speed. What is the average speed for the entire ride?
4.5 m/s
A 250kg snowmobile is traveling north at 12m/s. Suppose that 15s later it is going south at 18m/s. What is the acceleration?
.4m/s2
Calculate the momentum of a 45kg student bicycling at 8m/s east.
360kg*m/s
Forces exerted by objects touching are called ______.
contact forces
Gravity is a force of attraction between objects due to their __________.
Masses
A girl leaves a history classroom and walks 10 meters north to a drinking fountain. Then she turns and walks 30 meters south to an art classroom. What is the girl's total displacement from the history classroom to the art classroom?
20 meters south
The word ______________ is a term often used for negative acceleration.
Deceleration
Which has a higher momentum - a .058kg tennis ball traveling at 40m/s or a .62kg basketball traveling at 4.4m/s?
Basketball
F=m x a best describes which law of motion?
Second law of motion
If you spin an object tied to a string around your head, the string stays taut. This is an example of __________ force.
Centripetal
A puppy runs 15 m west and then runs back 3 m east in 6s total. What is the average velocity of the puppy?
2m/s west
Suppose a swimmer accelerates for .5s to reach a velocity of 3m/s forward. What is the swimmers average acceleration?
6m/s2
At what velocity must a 3000kg wrecking ball travel forward to achieve a momentum of 15,000kg*m/s?
5m/s
Explain the third law of motion. (hint: action-reaction force pair)
For every reaction there is an equal and opposite reaction.
If you stretch a rubber strap by pulling on it, it will pull back until it returns to the original length. This is an example of _________ force.
Elastic