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Principle of Moments When an object is EQUILIBRIUM (balanced forces), the sum of the ANTI - CLOCKWISE moment is equal to the sum of CLOCKWISE moment about the pivot.

CM = ACM

F * D = F * D

Answer in Nm

UNITS

Energy - Joules (J)

Weight (force) - Newtons (N) (mass*10)

Moment - Newton Metres (Nm)

Speed - m/s, cm/s, etc...

Momentum - Kgm/s

Acceleration - m/s^2

Density - g/cm^3 or kg/cm^3

Power - W

Radioactivity - Bq

Efficiency - %

Making Energy

Nuclear Fission This reaction is used to create heat to heat water in nuclear power stations. Fission means SPLITTING. Uranium is commonly used because of its large nucleus, which is easy to split. The uranium is hit with a neutron which causes it to split creating 2 smaller nuclei, and this creates a CHAIN REACTION. Power stations are designed so there is no explosion, which would happen if the reaction went out of control.

Nuclear Fusion This is when 2 atomic nuclei JOIN to create a large nucleus. This causes energy to be released.

This occurs naturally in our sun.

Nuclear Fusion is to expensive to use on a wide scale, because the temperatures need to allow the nuclei to move very fast would be very expensive. Therefore it is a long way off.

Things to Know