Simple Machines Calculations

You apply a force on a crowbar to open a stuck door. The effort length of the crowbar is 26 cm long and the resistance length is 4 cm. Find the MA of the crowbar

• 0.15
• 7
• 6.5
• 0.5

Three of your friends are all sitting on one end of a seesaw. The combined weight is 275 N. The length from the fulcrum to your friends is 2.5 m. The rest of the seesaw (from the fulcrum to you) is 4.5 m. What effort force is needed to lift your friends?

• 0.006
• 500
• 152.8
• 0.002

This machine has a flat slanting surface. We use it to push objects to a higher place more easily.

• Wedge

• Wheel and axle

• Inclined plane

• Pulley

What is the gear ration of this gear train?

•  $\frac{2}{25}$  

•  $\frac{25}{2}$  

•  $\frac{5}{1}$  

•  $\frac{1}{5}$  

Driver gear A rotates at 1500 rpm. Calculate the angular velocity of gear B.

• 300 rpm

• 2500 rpm

• 3750 rpm

• 600 rpm

Ideally, how much force would be required to lift the 125 Newton load?

• 62.5 N

• 25 N

• 31.25 N

• 500 N

What is the ideal mechanical advantage of this inclined plane?

• 3.35:1

• 3.2:1

• 0.3125:1

• 2:1

How much input torque would be required at gear A to generate 350 ft-lbs of output torque at gear D?

• 70 ft-lb

• 0.036 ft-lb

• 28 ft-lb

• 52 ft-lb

Ideally, how much effort force is required to lift the load?

• 40 lb

• 80 lb

• 20 lb

• 160 lb

Sprocket 1 has 20 teeth and rotates at 2000 rpm. Sprocket 2 has 50 teeth. Calculate the angular velocity of sprocket 2.

• 2500 rpm

• 1200 rpm

• 5000 rpm

• 800 rpm