Required Practicals Flashcards
(56 cards)
RP6 - Force and extension(8 Steps)
- Set up equipment, ensure spring will return to its original dimensions
- Adjust ruler so the zero mark is at the same height as top of the spring
- Record length of the spring when no weights are attached
- Hook a 1N weight on the bottom of the spring
- Record new length of the spring
- Add weights at 1N intervals recording the new length of the spring
- Calculate extension of spring when each weight is added by subtracting original length from recorded lengths
- Convert weights to masses: weight/9.81=mass(kg)
RP6 - How can the extension of a spring when a weight is added be determined?
Subtract the start length away from the length when weight has been added
RP6 - How could you determine the limit of proportionality for a spring?
- Add weights and measure extension
- Plot extension against force and loo for where the line is no longer showing a linear relationship
RP6 - How could you increase the accuracy of the limit of proportionality that you could determine in this experiment?
Use smaller intervals
RP6 - What improvement could be made to the investigation to ensure the length of the spring measured is accurate?
- Make sure spring is stationary before measuring length and use a pointed on the end of the spring to measure length
RP6 - How could you test after adding weights if the spring is still behaving elastically?
Remove the weights and see if it is still returning back to its original shape
RP6 - Safety precautions?
- Secure clamp stand on desk using G-Clamp
- Place tray of sand on the floor under the test spring
RP7 - Investigating the effect of varying the force on the acceleration of an object(5)
- Set up bench, pulley at end of bench, string to toy car from pulley, connect 2 light gates to the data logger
- Add a 1N weight to the pulley and release the trolley
- Light gates A and B will determine the velocity at each point and use this to calculate acceleration between the 2 points
- Record acceleration when 1N is added
- Repeat by adding more weights at 1N intervals
RP7 - Investigating the effect of varying the mass of an object on its acceleration(5)
- Attach a 10g mass on top of the toy car, connect 2 light gates to the data logger
- Add a 1N weight to the trolley and release it
- Light gates A and B will determine the velocity at each point and use this to calculate the acceleration between the 2 points
- Record the acceleration when 1N is added
- Repeat by adding more weights to the trolley at 1N intervals
RP7 - What is the equation that links acceleration, force and mass?
Resultant force = mass * acceleration
RP7 - When investigating the effect of the force on acceleration what is the dependent variable?
Acceleration of object
RP7 - What measurements are required to determine the acceleration of an object?
- Velocity at each light gate
- Time taken to pass from one to another
RP7 - Why do we use a sloping runway when investigating acceleration?
Compensate for friction
RP7 - What are the 2 advantages of using a light gate instead of a stopwatch?
- No reaction time error
- Results are taken automatically
RP7 - Why should the same trolley be used in each experiment?
There should only be one independent variable and so keeping this acts as a control
RP7 - What are possible variables when investigating the acceleration of a trolley on a ramp?
- Mass of trolley
- Force applied to trolley
- Gradient of ramp
- Material of ramp
RP7 - Why is it important to not push the trolley when you release it?
Same force applied to each trolley
RP7 - Equation for acceleration?
acceleration = 2 * distance/(time)^2
RP8 - Measuring the frequency, wavelength and speed of waves in a ripple tank
- Fill ripple tank so the water has a depth of 5mm, place ripple tank on top of a piece of paper or card
- Place a wooden rod on the surface of the water and attach it to power supply, add lamp to circuit and hold lamp above ripple tank
- View wave pattern from side of tank
- Measure wavelength: measure distance between two wavefronts with metre ruler perpendicular to them, divide by number of waves
- Measure frequency: use stopwatch and count number of waves passing a particular point over a fixed time, divide time by number of waves, then use frequency=1/period
- Calculate wave speed=frequency * wavelength
RP8 - Measuring the frequency, wavelength and speed of waves in a solid
- Wooden bridge on bench, string or elastic cord to vibration generator connected to power supply
- Switch on signal and vibration generator so string vibrates up and down and move the wooden bridge until a clear wave pattern is formed
- Wavelength measured: use a meter rule to measure distance between wooden bridge and vibration generator, count number of loops in wave pattern(divide distance by number of waves counted)
- Frequency measured: record frequency from signal generator
- Use equation wave speed=frequency * wavelength
RP8 - When investigating waves through a string, what are 3 control variables?
- Number of masses
- Length of string
- Type of string
RP8 - Why can it be difficult to measure the length of string between vibration generator and moveable wooden bridge?
- String is moving
- If distance is greater than 1m then 1 metre rule would not be long enough
RP8 - How could you adjust the experiment set up to show one complete wave through a string?
Move wooden bridge
RP9 - Investigating the refraction of light by different substances(8)
- Place a block on a piece of paper and draw around it
- Shine a ray of light through the block
- Mark the ray of light close to the point it leaves the ray box and where it enters the block
- Mark the ray of light at the point it leaves the block and further along this ray of light
- Join the points together to show the path of the light
- Draw the normal lines at 90 to the surface
- Use protractor to measure the angle of indicdence and angle of refraction
- Shine the light from the ray box at different angles by increasing the angle of incidence at 10 intervals
