Conservation Laws Review

Air resistance is a non conservative force which always opposes motion. You take a flight to California and back. The net work done by the air resistance is....

• negative for higher speeds

• negative for slower speeds

• zero

• positive for slower speeds

• Positive for faster speeds

A bomb explodes breaking into 3 pieces. one piece goes at 45 degrees north west. The second launches 45 degrees to the north east. Which way would the third piece go

• right

• up

• down

• 45 degrees south east

• 45 degrees south west

How much work is done in holding a 15 N sack of potatoes while waiting in line at the grocery store for 2 minutes?

• 15 J

• 45J

• 0 J

• 5 J

Which of these is are viable units for impulse? Select all that apply.

• J/s

• W

• N*s

• kgm/s

• kg*N

If the net work done on an object is negative, then the object’s kinetic energy

• decreases

• increases

• zero

• remains same

A roller coaster goes over a 10m high hill at 20m/s. What kind of energy does the roller coaster have (frictionless)? Select all that apply.

• potential

• kinetic

• electric

• thermal

• Spam

A 500 kg roller coaster goes over a 10m high hill at 20m/s. What is the total amount of energy the roller coaster has

• 100,000 J

• 49,000 J

• 149,000 J

• 51,000 J

Humpty Dumpty sat on a wall. Humpty Dumpty had a great fall. What is the speed of Humpty Dumpty right before he hits the ground?

• v=mgh

• V= 0.5mk²

• sq root (mgh)

• sq root (2gh)

A 1500kg car is speeding trying to get away from the cops. They are travelling a 50m/s when they lose control and crash into a tree coming to a stop. How much impulse did the car experience

• 75,000 N*s

• 30 N*s

• 9.8 N*s

• 0 N*s

A 1500kg car is speeding down the highway to escape the cops. They are travelling 50m/s until they lose control of the car and crash into a tree coming to rest. If the collision took 0.2s how much force was experienced?

• 375,000 N

• 75,000 N

• 9.8 N

• 0 N

• 15,000 N