Helpmyphysics

Roll your mouse over each of the members of the electromagnetic spectrum and find out how they are detected and used.

Use this downloadable sheet to record your research. Research sheet

Use the above momentum simulation to investigate the total momentum before and after the trolleys collide.

1. Click on the different stacked trolleys to change the mass of each vehicle`s mass.
2. Press the green triangle to play the simulation
3. Download the investigation sheet here Momentum investigation sheets.

Think of an object`s momentum as how hard or easy it is to stop the object from moving. Obviously it is much harder to stop a slowly rolling car than it is to stop a fast moving football.

Momentum depends on the object`s mass and velocity.

Momentum is a vector quantity which has units

Try out this revision on parts of a wave.

Here is a movie showing how an increase in mass of an object can affect the object`s acceleration.

From the above famous equation you can see that an increase in the mass, m, will reduce the acceleration provided the unbalanced force remains the same.

This is why your car will have a smaller acceleration when it is full of passengers than it would have when empty.

Click the start button below to see what can happen to your weight while inside a moving elevator.

Here are a couple of posters you can download to remind you of what the new National Courses.

Download N4 Course Summary here

Download N5 Course Summary here

Here is a quick summary poster on acceleration:

Download Acceleration Note Poster pdf here.

Here is the set up for an opamp set to differential mode.

This set up amplifies the difference between the two voltages.

Looking at the input and feedback resistors we have:

Click the green arrows of V2 and V1 and check out that the difference between V2 and V1 is multiplied by 2.

This is an example of a differential amplifier.

Here is an example of an operational amplifier. It is in inverting mode
Change the feedback resistor by moving the mouse over the black handle.
Click on it to reset it back to 1000 ohms.
You can vary the input voltage by clicking the green arrow.

Set the feedback resistor to 4000 ohms.

The gain of an inverting opamp is given by:
.

When the feedback resistor is set to 4000 ohms then the gain of the opamp is:

Click the green arrow of the input voltage and note the output voltage.
You can see that the output voltage is always multiplied by -4.

If you increase the input voltage too much the output voltage levels off at -15V.
This is when the amplifier reaches saturation because it cannot give an output voltage larger than the voltage of the supply that works it.

Move the black handle to give the feedback resistor different values and check the gain equation:
.