1a Pupil Resource Sheet Measuring Forces FACTFILE n The easiest way to measure force is with a Newton metre or spring balance. n Speed is measured by taking the time and dividing it into the distance travelled. n Air pressure is measured using either an aneroid or a mercury barometer. n In a mercury barometer the pressure of the air is registered on the mercury which moves up a scale. n In an aneroid barometer the pressure pushes onto a thin box of air and this moves a lever. Continue to 1b t 1b Pupil Resource Sheet Measuring Forces You are going to try to find the answers to these questions n How can you measure forces? n How can you measure the force of gravity? Continue to 1c t 1c Pupil Resource Sheet Measuring Forces NOW TRY THIS You will need: n A stop clock n A toy car n A slope that can be made of a piece of wood n A set of bathroom scales n A tin can with three holes in one side one above the other n A barometer n A spring and 4 weights of known weight n A metre rule Experiment 1 - Measuring the effects of force by measuring distance and speed of an object n Use the toy car a stopwatch and a slope. n Try to think of a way of always using the same force to push the car along. n Use your slope /plank of wood and lay it flat n Push the car along on the flat surface and measure the distance it travelled and the length of time it took n The speed is calculated by dividing the distance the car travelled by the time it took. n Write out the sum and your working out n What was the speed of the car? n Continue this experiment by making a gradual slope and a steep slope and repeat the measurements and record them n Record this on the chart on the next page Continue to 1d t 1d Pupil Resource Sheet Measuring Forces RECORD YOUR RESULTS Situation Distance Time Speed Car on flat Car on slope 1 Car on slope 2 Car on different surface n What was the effect on the car of the different situations? n Did friction play a part? How? Continue to 1e t 1e Pupil Resource Sheet Measuring Forces Experiment 2 - Force You will need a set of bathroom scales. n Hold the scales close to your chest with the scale showing on the outside n Ask your partner to read the scale while you pull the surface of the scale towards your chest with flat hands n What is the measure of the force of pressure that you are applying? n Try again. n Your partner should also do this record your results. Continue to 1f t 1f Pupil Resource Sheet Measuring Forces Experiment 3 - Pressure in liquids n Fill the tin can to the top with water. Do this over the sink . Watch the flow of water and the angle of the flow and draw the results. What force was working here? Continue to 1g t 1g Pupil Resource Sheet Measuring Forces Experiment 4 - Measuring the effects of the force of weight You will need a spring and a set of weights and a ruler n Draw a bar graph of your results with the weight on the y axis and the length that the spring stretched on the x axis n Measure the length of the spring without the weights and record it on your bar chart n Place a weight on the end of the spring it is best to start with the lightest weights first n Measure the length of he spring and record n Repeat the experiment with all the weights and draw your bar chart. n What can you now say about the spring and the weights? n Write this as a conclusion Continue to 1h t 1h Pupil Resource Sheet Measuring Forces NOW TRY THIS Look at the barometer with the teacher. n How does it work? n What does it measure? n Why is this useful information?