Worksheet

Work and Machines

1. a) Using a force to move an object.

b) A machine is anything, which makes it easier to do work.

2. a) Yes, because your using force to movie this object.

b) No, because your not using force while brushing your teeth.

c) Yes, because your using force while pushing down on the pedals.

d) No, because your not using force while reading a page.

 3. You must eat if you’re going to keep working because if your body is not filled with food you loose the energy in your body and if you keep loosing energy you’ll eventually break down or faint.

 4. They are called machines because it makes it easier to do work.  

     Pulleys, Gears and Other Wheels

 1.     To make a pulley system you need a set of pulley wheels and a rope.

2.     It is easier for a mechanic to list a car engine using a pulley system because he can lift a whole engine by just pulling a rope and that’s easier than carrying it with your bare hands.

3.     a) The chain transmits the force to the back wheels, turning them.

     b) The cycle’s gears change the number of times that a turn of the crankshaft turns the back wheels.

4.     The difference between high and low gear is that in high gear the chain runs over the small cog wheel at the back, but in low gear the chain now has to run over the large cog wheel at the back.

Building a Pyramid

1.     a) Wedges

b) Flat bottomed, barge like boats

c) Ramps

2.     a) The friction was reduced when the blocks were moved because they need to pull the block back up the ramp that caused a lot of friction they just had to put it in place.

b) The crane

3.     Picture in a separate piece of paper.

4.     They are used in construction sites to lift heavy objects like bricks or stone.

5.     A lot of force had to be used to lift the last block to the top of the pyramid.