Pupil sheet · Stretching springs

Stretching springs — final check

Name ______________________ Date ____________

Work alone, with the lesson closed. Answer every question; there are no hints.

1. calculate / state / explain / describe / determine

A pupil tests a spring for a toy. With the empty hanger on, the pointer reads 15.0 cm. She adds 100 g masses one at a time, and her readings are in the table. Take g = 9.8 N/kg. (a) Calculate the extension for each mass added. (b) State whether her extensions are proportional to the load, and explain how you know. (c) Describe the load–extension graph that her results give, with the load up the side. (d) She takes the masses off and hangs a key ring on the empty hanger. The pointer reads 18.5 cm. Determine the weight of the key ring. (e) Describe what the loads do to the size and the shape of the spring.

masses added / g	pointer reading / cm
0	15.0
100	17.8
200	20.6
300	23.4
400	26.2

(a) The extensions

(b) Proportional?

(d) The key ring

(e) The change to the spring

2. state / explain / calculate / identify

Supplement. A pupil loads a spring and records its extension, as in the table. (a) State whether the extension is proportional to the load for the first four rows, and explain how you know. (b) Calculate the spring constant of the spring, in N/m. (c) Identify the limit of proportionality. (d) Calculate the load that gives an extension of 5.0 cm. (e) Her partner writes: “k = 6.0 N ÷ 0.124 m = 48 N/m.” Explain the mistake.

load / N	extension / cm
0	0
1.2	2.0
2.4	4.0
3.6	6.0
4.8	8.7
6.0	12.4

(a) Proportional?

(b) The spring constant

(d) Load for 5.0 cm

(e) The partner’s mistake