Aforce of magnitude f stretches a spring a distance of 2 cm from its rest position. what magnitude of force will stretch the spring an additional 4 cm?

4f

2f

3f

0.5f

3F

Step-by-step explanation:

Force = k * x

so k = force/distance = F/2

if you were to duplicate the distance 2 times more, the F must also do so so that it's proportional

so F*2 = 2F but since it says additional 4cm, you will need to add the initial one and this one so that it's 6cm in total.

2F + F = 3F

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

the workers who do no drive has no reasonable reason to buy gasoline due to they don't have anything to use it for