Gravity is the force that pulls all objects vertically down. Each kilogram of mass experiences a force of around 9.8 Newton. If an object such as a cart is resting on a horizontal surface, the vertical force of gravity has no effect and the cart will not roll. When the surface is at an angle to the horizontal gravity has some effect on the cart and it will accelerate down the slope when released. The greater the angle of the slope, the greater the effect of the gravity on the trolley. This is shown below.
The aim of this activity is to discover how the effect of gravity down the slope depends on the angle of the slope. You will use equipment similar to that shown below. You will need to design the experiment so that you can determine if there is a relationship, you determine how many readings are needed, how many repeats and what is appropriate for the equipment you are using. You will be expected to identify sources of error and give error calculations.
You may want to use a bob line and attach the protractor to the plank to make the angle readings easier.
Enter your data onto an excel spread sheet. Use the graph wizard to plot your data.
…refer to your text
What is the weight (in Newtons) of the trolley.
At angle θ, what it the effective force acting parallel to the slope. (see sample problem 1.5, pp. 17)
Create a model of what you would expect the values to be. Remember in excel you have to convert angles in degrees to radians before you can use the trig. functions.
How do your results compare to the model?
Draw a vector diagram that illustrates the component vectors and use this to explain your results.