⚙️ Physics – Work and Energy (Points 1–20

Work

Product of force and displacement in the direction of force

Work formula

W = F × s × cosθ

SI unit of work

Joule (J)

CGS unit of work

erg

1 Joule

Work done by 1 N force over 1 m

Work is scalar

Only magnitude

Positive work

Force and displacement are in same direction

Negative work

Force and displacement are in opposite direction

Zero work

Force and displacement are perpendicular

Energy

Capacity to do work

SI unit of energy

Joule

1 Joule of energy

Energy needed to do 1 J work

1 kilojoule

1000 J

Kinetic energy

Energy due to motion

K.E formula

(1/2)mv²

Potential energy

Energy due to position or shape

P.E formula

mgh

PE depends on

Reference point (zero level)

Law of conservation of energy

Energy can neither be created nor destroyed

Mechanical energy

Sum of kinetic and potential energy

Power

Rate of doing work

Power formula

P = W/t

SI unit of power

Watt

1 Watt

1 Joule/second

1 kilowatt

1000 Watts