The Student Room Group

Physics Force constant question

A spring of force constant 300 N m-1 is cut in half. The two halves are then placed in parallel
with each other. A force of 6.0 N is then applied to this parallel arrangement.
What is the extension of each spring?
A 0.5 cm
B 1.0 cm
C 2.0 cm
D 4.0 cm

How is it A, i keep getting B using F=2kx?

Reply 1

so k is proportional to 1/L
so if L halves, k doubles = 600N m-1
since it is in parallel you have to add the spring constants, so k= 1200N m-1
f=kx
you get x as 0.5cm

Reply 2

Original post by mosaurlodon
so k is proportional to 1/L
so if L halves, k doubles = 600N m-1
since it is in parallel you have to add the spring constants, so k= 1200N m-1
f=kx
you get x as 0.5cm

Thanks, could you help me with another q pls,

* A resistance wire is coiled around a thermistor. The coil of wire will warm the thermistor. It is suggested that the relationship between the power P dissipated in the coiled wire and the stable resistance R of the thermistor is given by the expression P = kRn, where k and n are constants. Describe how an experiment can be conducted to assess the validity of this expression and how the data collected can be analysed to determine k and n. Use the space below for a circuit diagram.

How would i draw the diagram?

Reply 3

Reply 4


No he drew it wrong, i don't think you need two circuits.

Quick Reply