Physics ReviewPhysics Practice Problems Key

Question #1:

You walk 100 meters in 15 seconds. What was your average speed in meters per second?

Answer #1:

s=d/t s=100m/15ss=6.67 m/s

Question #2:

You travel by car from Mundelein to Glenview, Illinois. You travel the 22 miles in 32 minutes. What was your average speed in miles per minute?

Answer #2:

s=d/ts=22 mi/32mins=0.69 mi/min

Question #3:

You are riding your bicycle in a straight line at a constant speed of 12 km/h. Did acceleration occur? Please answer in a complete sentence.

Answer#3:

No. Acceleration did not occur because the bicycle did not change speed or direction.

Question #4:

You are riding your bicycle at a constant speed of 15 km/h around an oval track. Did acceleration occur? Please answer in a complete sentence.

Answer #4

Yes. Acceleration did occur because the bicycle changed direction.

Question #5:

A weightlifter completes a benchpress of 300 N. She moves the weight 0.54 m. Calculate the work the weightlifter completed.

Answer #5:

W=FdW=300N0.54mW=162J

Question #6:

A tractor pulls a 5000N force a distance of 2 m. Calculate the work the tractor did.

Answer #6:

W=FdW=5000N2mW=10,000J

Physics ReviewPhysics Unit Review Key

Question #1:What is force? List the types of forces acting on objects.

Answer #1:Force is any push or pull on an object. Common forces include applied, friction, air resistance, gravity, and normal.

Question #2:What is work? How do we measure work?

Answer #2:Work is a transfer of energy. Work is measured in Joules (J).

Question #3:What objects make work “easier”?

Answer #3:Simple machines make work easier.

Question #4:Give examples of the following simple machines: inclined plane, screw, wedge, and lever.

Answer #4:Inclined plane: RampScrew: screw, boltWedge: Axe Lever: teeter-totter, claw end of hammer

Question #5:Explain Newton’s Laws of Motion.

Answer #5:1st: Inertia; an object at rest will stay at rest or an object in motion will stay in motion unless acted on by an outside force.2nd: F=ma; to move a mass you need a force. The bigger the mass is the more force force one needs to apply.3rd: Action/Reaction; for every action there is an equal, but opposite reaction.

Question #6:What is the difference between speed and velocity?

Answer #6:Both speed and velocity are rates of distance per unit of time, however, velocity also indicates a direction.

Question #7:What is acceleration?

Answer #7:Acceleration is any change in the speed or direction of an object.

Question #8:Write down formulas used in this unit.

Answer #8:Speed s=d/tMomentum p=mvWork W=FdForce F=maDensity D=m/vVolume: Amount of space an object takes up.Surface area: The sum of all areas on a surface.