Name the simple machine exemplified by each thing:
Razor blade ____________________
Spiral stairs ____________________
A bolt ____________________
Pair of pliers ____________________
A 15,000N car needs to be moved to the
back of a truck 5 m above its initial location. Calculate the mechanical
advantage if 4,000N is applied to a cart to push it up a 20 m ramp.
What is the efficiency of the system above?
A rope is wound around the crank of a lawn
mower. The crank has a radius of 0.30 m. To start the mower, the
lawn boy exerts a force of 70N on it. What is the torque exerted by the
How much force is required to press down
on a pair of bolt cutters 0.64 m from the fulcrum if 400 N of force is
required to cut a hardened steel lock 0.07 m from the fulcrum?
Which moment of inertia equation would you use for each of the following?
Swinging a ball on a chain __________________
Swinging a baseball bat __________________
Rolling a hulla hoop down an incline __________________
Rolling a basketball down the court __________________
Tell if the following objects have rotational
equilibrium (R), translational equilibrium (T), both (B), or neither (N)
_____ A boat propeller, spinning at a constant velocity as the boat accelerates in the water.
_____ A fence post.
_____ A building.
_____ An asteroid traveling at a constant speed through space, while turning on its axis at a constant rate.
Compare two cylinders of equal mass and
diameter. One is solid the other is hollow. Which would accelerate faster?
Explain why in complete sentences.
How (and why!) would the force required
to open the classroom door change if you moved the handle from its present
position to the middle of the door? (Answer both questions (i.e., “how”
and “why” in complete sentences.)
T = F x l MA = Fout / Fin Efficiency = W out / W in
W = F x d Moment of Inertia: Check your notes
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