1) Inclined planes are always a ____________ multipliers and the mechanical advantage is always ____________.
- This inclined plane rises 3 m for every horizontal run of 4 m. Label below.
- The IMA is ____________ so it's a ____________ multiplier and it takes
2) A first class lever has the ____________ in between the ____________ and can be a ____________ multiplier, a ____________ multiplier, or a ____________ changer. This lever has an ideal mechanical advantage of 1.0 which means that both lever arms are ____________. If the efficiency is 80%, what is the AMA? __________ If the input displacement is 10 cm, the output displacement is ____________. If the input force is 20 N, the output force is ____________. An example of this type of lever is ____________.
3) A second class lever has the ____________ in between the ____________ and the ____________. It can be only be a ____________ multiplier. This one has an ideal mechanical advantage of 3.0 which means that the input lever arm is ____________ the output lever arm. If the efficiency is 75%, the AMA is __________. If the input force is 40 N, the output force is ____________. If the input speed is 20 cm/s, the output speed is ____________. An example of this type of lever is ____________.
4) A block and tackle pulley system has an ideal mechanical advantage of 6.0. It is a ____________ multiplier. Because of a lot of friction it has an efficiency of 50%. What is the AMA? ____________. If the input force is 50 N, the output force is ____________. If the input displacement is 20 cm, the output displacement is ____________. One can make a speed/displacement multiplier out of a pulley system by _______________ the input and output.
5) A door knob is an example of a ____________ that is a ____________ multiplier. Its IMA is 8 and has an efficiency of 75%. What is its AMA? ____________. If the input torque is 50 Nm, the output torque is ____________. If the input angular displacement is 2 radians, the output angular displacement is ____________. If the input linear displacement is 8 cm, what is the output linear displacement? ____________
6) A third class lever has the ____________ in between the ____________ and the ____________. It can be only be a ____________ multiplier. This one has a mechanical advantage of 1/3 which means that the input lever arm is ____________ the output lever arm. If the input force is 20 N, the output force is ____________. If the input speed is 10 m/s, the output speed is ____________. An example of this type of lever is ____________.
7) You use an inclined plane to lift your household contents from street level into a moving truck. Like all inclined planes, it is a ____________ multiplier. If its length is 5 m and it rises 1 m, what is the IMA? ____________. The efficiency is 80%. What is the AMA? ____________. If the weight of the washing machine is 800 N, what is the force required to move it up the incline? ____________. Rather than ____________ it vertically, you have to move it ____________ times as far but apply ____________ the force.
8) A bicycle is obviously a ____________ multiplier. A bicycle drive train in a particular gear has an IMA of 1/6 and the efficiency of a properly maintained drive train is close to 95%. If the input force from the foot is 300 N, the output force where the wheel contacts the ground is ____________. If the input speed at the feet is 2 m/s, the speed of the bicycle is ____________.
9) A car is moving at 20 mph and the wheel is rotating at 200 rpm. If the engine is rotating at 2000 rpm the IMA of the drive train is ____________ and it is a ____________ multiplier. Because of ____________ in the transmission, the horsepower from the engine is usually about 10% to 15% less than the horsepower at the wheel. Which horsepower is more practical? ________________________
10) A 110% efficient first-class lever has a 2.0 m input lever arm and a 0.5 m output lever arm. Sketch a detailed drawing below. What is the IMA? ____________ What is the AMA? ____________. If the input force moves 30 cm, the output force moves ____________. If there is a 500 N input force, what is the output force? _________. Thoughts about 110% efficiency?
11) A real lever is used to lift a heavy load. When a 50 N force pushes one end of the lever down 1.2 m, the load rises 0.2 m. Calculate the weight of the load if the efficiency is 90%.
12) An inclined plane is 6.0 m long and rises to a maximum height of 1.5 m. A 100 kg washing machine on a dolly is pulled up the inclined plane with a force of 300 N. Sketch a detailed drawing below. What is the IMA? ______ What is the AMA? ____________ What is the efficiency? ____________ What is the % efficiency? ____________
13) An 80% efficient second-class lever has a 2.0 m input lever arm and a 0.5 m output lever arm. Sketch a detailed drawing below. What is the IMA? ____________ What is the AMA? ____________. If there is a 500 N input force, what is the output force? _________
14) A 50% efficient third-class lever has a 0.5 m input lever arm and a 2.0 m output lever arm. Sketch a detailed drawing below. What is the IMA? ____________ What is the AMA? ____________. If there is a 500 N input force, what is the output force? _________ If the output force moves through 20 cm, the input force moves through ____________ cm.
15) An inclined plane has an efficiency of 80% and rises to a height of 1.0 m. A 500 N refrigerator is transported up the incline with an applied force of 100 N. What is the length of the incline? Sketch the situation below.
16) A pulley system has an IMA of 3. Sketch the pulley system below. If the efficiency is 80% and the 140 pound woman wants to lift a 250 pound engine out of a car, with what force must she pull? ____________ If she wants to lift the engine 1.0 m, how much rope must she pull? ____________ Can she do it? _______ Explain.
17) A scissors jack with an IMA of 50 is used to lift a car. Sketch and label below. Because of enormous amounts of friction, its efficiency is around 60%. You are lifting half of a 2 metric ton car so your input force must be __________ N. If you want to lift it 40 cm, over what distance must you apply the force? __________ m. Will most adults be able to use this jack? Explain.
18) A 60% efficient blabuhdeeblahblah machine has an IMA of 0.10.
What is its purpose?
An input force of 400 N results in an output force of __________ N.
An input speed of 10 m/s results in an output speed of __________ m/s.
Why did I use that name for this machine?
19) In raising a 3000 N piano with a pulley system, the workers note that for every 2 m of rope pulled down, the piano rises 0.4 m. Sketch the pulley system below. What is the IMA of the pulley system? ____________ How much force is required to lift the piano if there is no friction? ____________ If the worker actually pull with 1000 N of force to lift the piano, what is the efficiency of the pulley system? ____________
20) A rear wheel on a bicycle has a 2.00 m circumference. The chain is attached to a gear on the wheel that has a 30 cm circumference and applies a 700 N force to the gear. Sketch the machine below. What type of machine is this? ____________ What is the IMA? ____________ What is the AMA if it is 95% efficient? ____________ What is the output force applied by the wheel at the ground? ____________ .
21) An automobile jack supplied by the manufacturer in most cars requires you to rotate an input lever that turns a screw and allows several levers to lift the car. The input radius of the wheel and axle is 30 cm and the jack lifts 1 cm for each turn of the input. What is the IMA? _______________ What is the AMA if it is 70% efficient? _______________ If you can apply a force of 100 N, what is the maximum weight that the jack can lift? _______________
22) An excavator has an actual mechanical advantage of 0.2. It is a _______________ multiplier but its true purpose is to be a _______________ multiplier and move a load a large _______________. If a 400 kg load is to be lifted, a _______________ N force must be applied. The excavator hydraulics are like our muscles, they are capable of huge _______________ but only over short _______________. An input displacement of 1 m results in an output displacement of _______________ m.