Formulae

Question 1

Weight=

Answer 1

=mass*gravitational field strength

W=m*g

Question 2

Work done=

Answer 2

=force *distance(along the line of force)

W=F*s

Question 3

Power=

Answer 3

=energy transferred / time (P=E/t)

=work done / time (P=w/t)

=potential difference * current (P=V*I)

=current^2 * resistance (P=I^2*R)

Question 4

Force applied to a spring=

Answer 4

=spring constant * extension

F=k*e

Question 5

Moment of force=

Answer 5

=force * distance (normal to direction of force)

M=F*d

Question 6

Pressure=

Answer 6

=force normal to a surface/area of that surface

p=F/A

Question 7

Distance travelled =

Answer 7

=speed * time

s=v*t

Question 8

Acceleration =

Answer 8

=change in velocity / time taken

a=(v-u)/t

Question 9

Resultant force=

Answer 9

=mass * acceleration

F=m*a

Question 10

Momentum=

Answer 10

=mass * velocity

p=m*v

Question 11

Kinetic energy=

Answer 11

=0.5 * mass *velocity^2

Ek=0.5mv^2

Question 12

Gravitational potential energy=

Answer 12

=mass * gravitational field strength * height

Ep=mgh

Question 13

Efficiency =

Answer 13

=useful output energy transfer / total input energy transfer

=useful power output / total power input

Question 14

Wave speed=

Answer 14

=frequency * wavelength

v=f*wl

Question 15

Charge flow=

Answer 15

=current * time

Q=I*t

Question 16

Potential difference=

Answer 16

=current * resistance

V=I*R

Question 17

Energy transferred =

Answer 17

=power * time (E=P*t)

=Charge flow * potential difference (E=Q*V)

Question 18

Density =

Answer 18

=mass / volume

ρ=m/v

Question 19

Resistance=

Answer 19

Potential difference/ current

Question 20

Pressure in a liquid=

Answer 20

=height of column of liquid * density * gravitational field strength
p=hρg

Question 21

Force=

Answer 21

=change in momentum / change in time

F=(m*Δv) / Δt