Forces

Belinda brought one rod magnet near to some steel pins. She recorded the number of steel pins attracted to the different parts of the rod magnet in the table below. She then made four markings on the rod magnet and labelled them as A, B, C and D.

Based on the table above, which diagram correctly shows the markings that Belinda made on the rod magnet?

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Noah has four magnets, L, M, N and O. He then brought each magnet near a pile of thumbtacks. The table below shows the number of thumbtacks attracted by the magnets from various distances.

Based on the results of his experiment, which of the following statements is/are true?

A - Magnet O is stronger than magnet M.

B - Magnet L is stronger than magnet N.

C - Magnet O is as strong as magnet N.

D - Magnet M is the weakest magnet.

• A only

• A and D only

• B and C only

• A, B, C, D

Joe conducted an experiment to find out how the lengths of different springs, W, X, Y and Z, change when a mass of 100 g was hung/placed on each spring. He then plotted a graph as shown.

Based on the information in the graph, which statements is/are true about the springs?

A - Spring Y was compressed.

B - Spring X stretched more than spring W.

C - Spring W extended to twice its original length.

D - Spring Z needed a mass more than 100 g to stretch or compress it.

• A only

• C and D only

• A, B and D only

• A, B, C and D

The graph shows the relationship between the length of a spring and the mass of the weight hung on it.

What is the extension of the spring when a 100-g weight is hung on it?

• 2 cm

• 4 cm

• 6 cm

• 8 cm

The diagram shows a wooden block being released from the top of a ramp made of material W. The time taken for the block to reach the bottom of the ramp is measured.

The experiment is then repeated with ramps made of materials X, Y and Z. The results are recorded in the table.

Based on the table above, which material, W, X, Y or Z, has the roughest surface?

• W

• X

• Y

• Z

The diagram shows a pan attached to a spring.

Justin added different number of marbles onto the pan and recorded the extension of the spring in the table.

What would the length of the spring be when 12 marbles were placed on the pan?

• 26

• 30

• 34

• 38

The graph shows the length of two springs, X and Y, when different loads are hung on them.

Study the graph carefully. Which of the following statements is/are correct?

A - Both springs have a length of 2 cm before

any load is hung.

B - For the same amount of load hung, spring X

extends more than spring Y.

C - When 250 g of mass is hung on each spring, spring X becomes 10 cm longer than spring Y.

• A only

• B only

• A and B only

• A and C only

A load is pulled with the same force over four different surfaces, P, Q, Rand S. The graph shows the distance moved by the load over time.

Which of the following statements are true?

A - Surface Q is the smoothest.

B - Surface R is rougher than surface S.

C - The friction between surface S and the load is

the least.

D - The type of surface affects the amount of friction between the load and the surface.

• A and B only

• C and D only

• A, B and C only

• B, C and D only

The diagram shows a ripe durian dropping from the tree at a certain height.

Which graph correctly shows the amount of gravitational force acting on the durian when it drops?

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Wendy set up an experiment as shown below to test the strength of four bar magnets, W, X, Y and Z. She suspended an iron ball with an elastic band. When she placed magnet W below the iron ball, the elastic band extended and the ball moved downwards.

She measured and recorded the distance between the iron ball and the magnet. She repeated the experiment using magnets X, Y and Z, and recorded the results as shown below.

Which of the following shows the strength of the magnet from the weakest to the strongest?

• W, X, Z, Y

• X, Y, W, Z

• Z, X, W, Y

• Y, Z, W, X