Name___________________________ IGCSE-Hooke’s Law Worksheet Answers

1.1.

1.2.

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F = k . x

Therefore k = F/x…..

k1 = k2 therefore

F1/x1 =F2/x2

100/10 = m /20

10 m = 2000…. M = 200g

Or

If 100g causes an extention of 10cm than 200g should cause an extension of 20cm

X = 20cm -10cm = 10cm

Spring 1 X = 30cm -10cm = 200cm

Spring 2

ans

ans

1.3.

1.4.

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15.2 cm + 2.1 = 17.3cm

Mass is the same

Weight is the same

Volume is different

Density is different

ans

1.5.

1.6.

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From graph, 400N on planet P has a mass of 40 kg.

Mass does not change.

From the graph 40kg has a mas of 200N in planet Q

ans

2.1.

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X = 16.4 cm – 15 cm

X= 1.4cm

From graph an extension of 1.4 =3.5 N

ans

F = 9N – 7N (opp. Direction- subtract)

= 2N left

2N left

F = m x a

a = F/m = 2/ 0.5kg = 4m.s-2

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X = 1

X = 1

X = 1

X = 1

X = 1

X = 1

X = 1

X = 0.8

X = 0.8

X = 0.8

X = 1

X= 1.2

X = 1.4

X=1.6

X = 0.8

X = 0.8

X = 0.8

X = 1

X= 1.2

X = 1.4

X=1.6

X = 1.1

X = 1.1

X = 1.1

X = 1.1

X= 1.1

X = 1.1

X=1.1

Student B

The extension for an increase of 0.5 N is costant for student A,C and D but is not always constant for student B

1cm

6.7 cm – 1cm = 5.7 cm

2.2.

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extenstion

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2.3.

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directly proportional

Newton

From the graph a load of 2.5 N causes an extension of 25mm. The total length of the spring is 50mm ( original length) + 25mm = 75mm

75mm

The force of gravity pulls it down

It has magnitude and direction

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Spring 1. From the graph a force of 10N causes an extension of 12.5mm in spring 1 and an extension of 15mm in spring 2.

After point P the graph is no longer straight

P

From the graph the extensions are 19mm and 26mm. The difference in extension is 7mm

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16 29 3 26 16 24 46

Error on load 3

Limit of proportionality has been reached

Find the original length of the spring. Measure the new length of the spring when it has a load. Subtract the measured length from the original length.

4.1. What is the extension of the spring? (1)

X = 20mm – 32mm = 12 mm

4.2. If the spring obeys Hooke’s Law, what does it tell you about the

extension and the load? (2)

The extension is directly proportional to the load.

4.3. What would the extension be if there was a 6N load? (2)

F = k . x

Therefore K = F/x…..

k1 = k2 therefore

F1/x1 =F2/x2

8/12 = 6 /x

8x = 48…… x = 6mm

4.4. As the weights are added the spring reaches its elastic limit. How

does this affect the spring? The extension and the load will not be directly proportional anymore

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