Paper 2 required practicals

RP6 - Determine the correlation between the mass placed on a spring and the spring’s extension by measuring resultant spring lengths

1. Set up a clamp stand with two bosses securing two clamps onto the stand. Place a heavy weight onto the stand to stop it from falling over.

2. Attach a metre ruler vertically to one clamp and a spring to the other

3. The top of the spring must be on the zero point on the ruler

4. The bottom of the spring has a pointer that is horizontal, pointing towards the ruler

5. Measure and record the position of the pointer on the metre ruler - this is the unstretched length of the spring (with no force attached)

6. Hang a 1N weight onto the spring and measure and record the position of the pointer on the metre ruler

7. Continue to add weights increasing in 1N onto the spring and measure and record the position of the pointer on the metre ruler

8. Calculate the extension caused by each weight by subtracting the unstretched length to the stretched length (with the weight attached)

9. Plot a graph of the extension against the weight

There is a linear relationship between force applied and extension of spring, until the spring is stretched past its limit of proportionality.

force = spring constant x extension

This practical can be used to work out the weight of a mystery object by plotting a graph and seeing the extension caused by the object, and seeing what weight that correlates to.

This practical can also be used to determine if something has been deformed elastically or inelastically (if inelastically there will not be a linear relationship but instead a curve).

RP7 - Investigate the effect of varying the force on the acceleration of an object of constant mass.

1. Set up a toy car attached to a piece of string. The string must be looped around a pulley. The other end of the string must be connected to a 100g mass.

The weight of the mass will provide the constant force acting on the toy car.

2. Set up a timer.

3. On the desk draw horizontal lines 10 cm apart.

4. Hold the toy car at the starting point (0cm)

5. Let go of the car

6. The weight provides a resultant force to the car, so the car will accelerate. Using the stopwatch record the times that the car passes each distance marker.

7. Repeat the experiment several times, reducing the mass on the end of the string each time.

However, as we are investigating the affect on a constant mass, the mass taken off needs to be added back onto the car so that the mass of the overall object (the toy car, the string and the weight on the end of the string) remains constant, despite the force changing (the weight on the end of the string).

We will find that (according to Newton’s second law) the force acting on the car is directly proportional to the acceleration of the car

RP7 - Investigate the effect of varying the mass of an object on the acceleration produced by a constant force.

1. Set up a toy car attached to a piece of string. The string must be looped around a pulley. The other end of the string must be connected to a 100g mass.

The weight of the mass will provide the constant force acting on the toy car.

2. Set up a timer.

3. On the desk draw horizontal lines 10 cm apart.

4. Attach a mass to the toy car and hold it at the starting point

5. Release the car and using the timer record the times that the car passes each distance marker.

6. Repeat the experiment increasing the mass added to the toy car

We will find that the acceleration of the object is inversely proportional to the mass of the object (according to Newton’s second law).

RP- 8