Friction
Momentum & Energy
Kinematics
100
What does mu stand for?
The coefficient of friction. Stickiness. Usually between 0 and 1, the higher the number, the more friction.
100
Michael pushes a football player across and out of the football field. Assume his force is 50 N and the distance is 45 meters. How much work is done?
W=Fd Work = 2250 J
100
How far will a car go if it accelerates at 5 m/s^2 for 10 seconds, and it starts from rest?
250 meters
200
What is the normal force, and how does it play in to the idea of friction?
The normal force is a reactionary force that points perpendicularly out of a surface that keeps the object from passing through the surface. The more normal force and object feels, the more friction resists motion.
200
In the movie "Date Night" Steve Carell backs his car into another car and the two stick and move together. This collision is referred to as what?
Inelastic Collision
200
A Honda Civic is approaching a red light. A Ferrari is stopped at the red light. As soon as the Civic reaches the intersection the light turns green. If the civic was moving at 10 m/s and then pushes the accelerator to 4 m/s^2, and the Ferrari pushes the accelerator to 10 m/s^2. Who would win a 500 meter race?
The Ferrari gets there 3 seconds ahead.
300
What is the static friction on a 5 kg object sitting on a flat surface. The coefficient of static friction is 0.8.
40N
300
In the movie "King Kong" Kong is standing on top of the Empire State Building which is 381 meters tall. The monkey's mass is 2000 kg. What is his gravitational potential energy?
What is 7,475,220 Joules. The formula is PE = mgh.
400
An object is being pushed on with a 500N force. The object has 50 kg of mass. The coefficient of static friction is 0.9. The coefficient of kinetic friction is 0.5. Will the object move? If so, with what acceleration?
Yes. 5 m/s2
400
Ms' O'Halloran's pickup truck has a mass of 2250 kg and has a velocity of 25 m/s to the south. What is the momentum of Ms. O'Halloran's truck?
What is 5.6 e4 kg m/s to the south
500
A matchbox car is loaded into a spring launcher. The spring has k=100N/m and is compressed 10cm. The car has mass 50g, and experiences a coefficient of static friction of 0.3. How far will the car go when the spring is released?
3.33 meters
500
Starting from rest in The Rugrats Movie, Dil Pickles zooms down a slide (pretend it is frictionless) from an initial height of 3 m. What is his speed at the bottom of the slide? Assume he has a mass of 25 kg.
What is 7.67 m/s
M
e
n
u