0654_2019__ON_QP_21_Phys

28. The diagram shows the two horizontal forces acting on a toy car of mass 2.0 kg that is moving

along a horizontal floor.

What are the resultant force on the car and its acceleration?

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29.Diagram 1 shows a spring with its length indicated. Diagram 2 shows the same spring with a 20 N

load hung from it, and the new length of the spring.

The spring obeys Hooke’s Law.

Which graph is the extension-load graph for the spring?

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30.An engine is doing work on a car as the car moves along a road.

Which two changes must result in less work being done on the car by the engine?

• decreasing the engine’s force on the car and decreasing the distance moved by the car

• decreasing the engine’s force on the car and increasing the distance moved by the car

• increasing the engine’s force on the car and decreasing the distance moved by the car

• increasing the engine’s force on the car and increasing the distance moved by the car

31. A machine has useful output energy of 1000 J, and wasted energy of 300 J.

Which expression is used to calculate the efficiency of the machine?

• $\frac{300}{\left(1000+300\right)}\times100\%$

• $\frac{300}{1000}\times100\%$

• $\frac{\left(1000-300\right)}{1000}\times100\%$

• $\frac{1000}{\left(1000+300\right)}\times100\%$

32. The more energetic molecules of a liquid are escaping from its surface, causing the liquid to cool.

What is happening to the liquid?

• It is boiling.

• It is condensing.

• It is evaporating.

• It is melting.

33. A transverse wave is travelling through a medium in the direction shown.

In which direction do the particles of the medium vibrate?

• parallel to the line joining P to Q

• parallel to the line joining Q to R

• perpendicular to the line joining P to Q

• perpendicular to the line joining Q to R

34. A glass block is surrounded by air.

Light travelling in the glass block reaches the edge of the block.

The critical angle of the glass is 42°.

Which row shows an angle of incidence i of the light and what happens to the light when it

reaches the edge of the glass block at this angle of incidence?

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35. There is a current of 6.0 A in an electric heater.

How much electric charge passes through the heater in one minute?

• 0.10 C

• 6.0 C

• 10 C

• 360 C

36. Which row shows how lamps are connected in a lighting circuit in a house and gives an

advantage of connecting them in this way?

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37. An electric kettle is rated at 3.0 kW and is connected to a 250 V supply. The kettle is switched on

for 2.0 minutes.

Which row shows the current in the kettle and the energy transferred by the kettle?

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