Elasticity - Jamb Physics Past Questions and Answers

Question 6:

• JAMB 1983

The total length of a spring when a mass of 20g is hung from its end is 14cm, while its total length is 16cm when a mass of 30g is hung from the same end. Calculate the unstretched length of the spring assuming Hooke's law is obeyed.

A. 9.33cm
B. 10.00cm
C. 10.66cm
D. 12.00cm
E. 15.00cm

Question 7:

• JAMB 1985

Which of the following statements are true about the spring balance and the chemical balance? i. both are used to measure the mass of an object. ii. either of them may be used to measure the weight of an object. iii. the spring balance works on the principle of Hooke's law while the chemical balance works on the principle of moments. iv. a change in gravity does the readings of a spring balance but not that of a chemical balance.

A. I, and iv
B. Ii and iii
C. Ii and iv
D. I, ii and iii
E. I and iii

Question 8:

• JAMB 1985

A force of 100N stretches an elastic string to a total length of 20cm. If an additional force of 100N stretches the string 5cm further, Find the natural length of the string

A. 15cm
B. 12cm
C. 10cm
D. 8cm
E. 5cm

Question 9:

• JAMB 1987

A load of 5N gives an extension of 0.56cm in a wire which obeys Hooke's law. What is the extension caused by a load of 20N?

A. 1.12cm
B. 2.14cm
C. 2.24cm
D. 2.52cm

Question 10:

• JAMB 1987

A 50kg block is dropped from a point 10cm above as shown in the fig above. if the force constant of the spring is 4.0 x 10⁴Nm^-1, find the maximum compression of the spring
[g = 10ms^-2]

A. 1.25m
B. 0.50m
C. 0.25m
D. 0.05m