The diagrams show four distance–time graphs.

Which graph represents the motion of an object that is at rest?（含图）

The diagram shows a force of 200 N pulling an object up a slope. The object moves 5.0 m along

the slope.

The object moves 3.0 m vertically upwards and 4.0 m horizontally, as shown in the diagram.（含图）

White light passes through a glass prism and produces a spectrum.

Which diagram shows the paths of the red light and the violet light?（含图）

liquid as quickly as possible. There are two possible positions for the cooling unit, P and Q. The

positions are shown in the diagram.（含图）

How does cooling affect the density of the liquid and what is the best position for the cooling unit?（含图）

What is the nature of this wave and what is the direction of vibration of the ground as the P-wave

passes through it?

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