# Push and Pull Forces

1. Mar 11, 2014

### DJLambo2K

Hello,

I'm new to this forum with little knowledge of physics.

Does anyone know how to calculate the force created by pushing and pulling on object (i.e. a car stuck in the snow) versus pushing versus pulling?

I.e., which of the three forces is the greatest?

My physical experience tells me that when I rock (push and pull) a vehicle stuck in the snow it results in a much superior force to move the vehicle versus solely pushing or less so, pulling.

Many thanks,
Andre

2. Mar 12, 2014

### CWatters

Rocking a car to get it out of a snow hole is an example of resonance. If you aren't familiar with resonance then you need to read up on that.

Many systems have a natural resonant frequency. If a source of energy (you) apply a force at the resonant frequency of the load (the car in the hole) it will absorb the maximum amount of energy from the source. The amplitude of oscillation will also be at a maximum. Once the amplitude of the oscillation reaches the depth of the hole it will come out.

The situation is similar to a man pushing a child on a swing. To get the child to swing higher and higher the man pushes the child at the resonant frequency of the swing (which can be modelled as a pendulum).

3. Mar 15, 2014