M A S T E R P A G E
Landslide Activity Sheet
(key)
2.4d
Date:
1. Why do you think the scales measure less weight as one end of the ramp is raised?
Some of the weight is acting along the ramp. The scale doesn’t record that weight.
2. At what height or what angle does the dry sand slide?
40-50 cm, or about 30 degrees.
Why do you think it slides then, in terms of forces?
The force of gravity along the ramp is greater than the frictional forces.
3. What effect does the simulated earthquake (knocking on the ramp) have on the dry sand?
The sand slides a bit with each knock.
Why do you think the simulated earthquake has that effect?
It must reduce the frictional forces because gravity remains constant.
4. Before testing wet sand, what effect do you think wetting the sand will have on the slide angle? Why?
It will probably slide more easily because the water reduces the friction.
5. What effect did wetting the sand have on its slide angle? Why?
The sand seemed to stick to the ramp, so it required a sharper angle to make it slide.
Surface tension causes the sand to adhere to the ramp.
6. What effect does the simulated earthquake (knocking on the ramp) have on the wet sand?
It slid further with each knock.
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