S3 Physics Equations

Question 1

Moment of a force

NOTE: this is the same as torque

Answer 1

Moment = F x Perpendicular distance

If not 90deg angle

Moment = F r sinσ

Question 2

Pressure =

Answer 2

Force/Area

Question 3

Stress =

Answer 3

Force / Area

Question 4

Strain =

Answer 4

= Change in length / Original Length

= e/l

Question 5

SUVAT EQUATIONS (5)

Hints….

v=
v²=
s=
s=

Answer 5

v = u + at

v² = u² + 2as

s = ut + ½at²

s = ½(u+v)t

Question 6

F =

(N2L)

Answer 6

ma

Question 7

Momentum =

Answer 7

mv

Question 8

Impulse =

Answer 8

Ft

Force * time

(Has units of Ns)

Question 9

Work done (W) =

(What is work done also equal to?)

Answer 9

Fs

Work is also equal to the change in kinetic energy

Question 10

Power =

(2 equations for power)

Answer 10

P = Fv

P = w/t

Question 11

Impact velocity of an object in free fall?

Answer 11

v = ROOT 2gh

Question 12

Resitivity formula

Answer 12

R = pl/A

note here that R - resistance and p - resistivity

Question 13

Ohms Law

Answer 13

V = IR

Question 14

I =

Answer 14

P/V

Question 15

I² =

Answer 15

P/R

Question 16

What is the definition of 1 volt

Answer 16

1 volt = 1 joule / 1 coulomb

Question 17

What is coulombs law

Answer 17

F = k q1q2/r²

Force = Constant X (Charge 1 x Charge 2 / Distance between charges squared)

Question 18

Magnitude of electric field from a point charge

Answer 18

k q1/r^2

Question 19

Field strength =

Answer 19

Force from q1/charge on object 2

Question 20

What is current in words

Answer 20

Change in charge over change in time

Question 21

Vp =

Answer 21

k Q/r

Question 22

Vq =

Answer 22

1/2 m v²