Work, Power and Energy Formulas
1. Work Done by Constant Force
W = FS cos Ө
It is a scalar quantity
2. Work done by Multiple Forces
W = W1 +W2+W3+….
Work done on the particle is the sum of the individual work done by all the forces acting on the particles.
3. Dimensions of work
Work = [ML2T-2]
4. Kinetic Energy
As mass is a positive quantity kinetic energy is a positive quantity.
K = ½ mv2= p2/2m
p is the linear momentum
5. Potential Energy
F = -dU/dx for conservative forces
UGravitational = mgh
Uspring =(1/2) kx2
6. Work energy theorem
According to the theorem, the change in kinetic energy of a body is the net work done by the net force on the body
W= ∆K
7. Mechanical energy
Mechanical energy E of an object or a system is the sum of kinetic energy K and potential energy U.
E= U+K. Conserved if forces are conservative in nature
8. Power
Pav = W/t ,
Here W is the work done and t is the time taken
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