Page 64 -

Unit summary

Revise!

1. The equation of Hooke’s Law for a vehicle 9. A shock absorber spring is compressed by 4 mm
suspension spring is F = 200 Δl . What is the under the effect of a 400 N force. What will the
el
elastic force if the spring is stretched by 10 cm? spring’s compression be under a 1.6 kN load?
textbooks nis edu kz
Express the result in cm.
2. What force must be applied to a spring of
coefficient 120 N/m to stretch it by 30 cm? 10. The elastic force vs. deformation graphs of two
different springs, 1 and 2, are shown in the graph
3. How much is a spring of coefficient 100 N/m
below . Compare the coefficients of these springs.
stretched, if the elastic force equals 20 N?
How many times does the second spring’s
4. What is a spring’s coefficient if it is stretched by coefficient differ from that of the first spring?
10 cm under the effect of a 5.0 N elastic force?

5. A 40 kg girl jumps on a pogo stick and
compresses it by 12 cm. Calculate the coefficient F el 2
of the spring of the pogo stick.
1

0
Δl

11. Imagine the year is 2035. You are a cosmonaut
participating in a mission to Mars. On your
way there you land on the Moon to carry out
experiments under a gravity force that is less than
on the Earth. You are responsible for measuring
rock sample masses. You can only take a spring
dynamometer for your investigations.

a) Compare the dynamometer’s spring extension
if the mass of rock is the same on the Earth, on
the Moon and on Mars.
6. Scales with a spring of 600 N/m coefficient are used b Describe how you ensure that your
for weighing fish. What is the mass of fish if the measurements are correct.
spring is compressed by 3 cm?
c) Show your measurements and calculation
7. A 10 kg load is suspended on a spring, and the
data on the graph.
spring’s length stretches to 80 cm. Then a further 4 kg
load is added, stretching the length of the spring d) Using your knowledge of Hooke’s Law and
to 82.5 cm. What is the coefficient of the spring? the characteristics of planets, create a booklet
Calculate the length of the non-deformed spring. for your fellow cosmonauts containing a
set of instructions on how to carry out the
8. A dynamometer spring is stretched by 5 mm under experiment and make the calculations.
the effect of a 6 N force. Find the mass of the load
suspended from the dynamometer that leads to the
spring being stretched by 14 mm.

64