1. A box that weighs 50 kg is pulled 7 m up an inclined plane with a force on 250 N to a vertical height on 3 m. Calculate the mechanical efficiency of this machine.
2. Why is the mechanical efficiency of a machine always less than 100%?
3. Explain how adding wheels and lubricants to a machine can help improve its efficiency?
4. It takes 700 J of energy to lift a box to a vertical height of 3 m. Determine which of the following systems would give the greatest mechanical efficiency to perform this task and should therefore be used.
a) The effort arm of a lever is pushed through 5 m with a force of 175 N.
b) The box is pushed up 8 m with a force of 120 N.
c) A force of 120 N is exerted on the rope of a pulley, which is attached to the box, and the rope moves 6 m.
5. A lever is used to lift a box to a vertical height of 20 cm. 40 N of force are applied through 50 cm to do this. How much energy is wasted as heat? (The force of gravity acting on the box is 75 N.)
6. It takes 250 N to pull a cart up a 10 m inclined plane to a vertical height of 2.5 m. The force of gravity acting on the cart is 600 N. Determine the efficiency of the machine to the nearest whole number.
1. A box that weighs 50 kg is pulled 7 m up an inclined plane with a force on 250 N to a vertical height on 3 m. Calculate the mechanical efficiency of this machine.
2. Why is the mechanical efficiency of a machine always less than 100%?
3. Explain how adding wheels and lubricants to a machine can help improve its efficiency?
4. It takes 700 J of energy to lift a box to a vertical height of 3 m. Determine which of the following systems would give the greatest mechanical efficiency to perform this task and should therefore be used.
a) The effort arm of a lever is pushed through 5 m with a force of 175 N.
b) The box is pushed up 8 m with a force of 120 N.
c) A force of 120 N is exerted on the rope of a pulley, which is attached to the box, and the rope moves 6 m.
5. A lever is used to lift a box to a vertical height of 20 cm. 40 N of force are applied through 50 cm to do this. How much energy is wasted as heat? (The force of gravity acting on the box is 75 N.)
6. It takes 250 N to pull a cart up a 10 m inclined plane to a vertical height of 2.5 m. The force of gravity acting on the cart is 600 N. Determine the efficiency of the machine to the nearest whole number.