Equations to know: Easy Edition

Question 1

What equation is used to calculate HF?

Answer 1

HF = φ + ek, where φ is the work function and ek is the kinetic energy.

Question 2

What equation is used to calculate the energy of a Photon?

Answer 2

E = hc/λ where h is planck’s constant (of value 6.626 times 10 to the negative 34th power), c is the speed of light (of value 3 times 10 to the power of 8) and λ is the wavelength.

Question 3

What equation is used to calculate moment/turning force?

Answer 3

Moment = Fd where F is Force and d is distance.

Question 4

What equation is used to calculate work done?

Answer 4

Work done = Fd where F is Force and d is distance, work done is energy transferred by a force.

Question 5

What equation is used to calculate speed?

Answer 5

s = d/t where d is distance and t is time.

Question 6

What equation is used to calculate acceleration?

Answer 6

a = v/t where v is velocity/speed and t is time.

Question 7

What equation is used for Newton’s 2nd Law?

Answer 7

F = ma when m is mass and a is acceleration.

Question 8

What equation is used to calculate Kinetic Energy?

Answer 8

KE = .5mv2 where .5 is half, m is mass, velocity is v which is squared.

Question 9

What equation is used to calculate Gravitational Potential Energy?

Answer 9

GPE = mgh where m is mass, g is gravity taken as 9.8ms-1 and h as height.

Question 10

What equation is used to calculate Power?

Answer 10

P = E/t where E is Energy transferred and t is time.

Question 11

What equation is used to calculate efficiency?

Answer 11

Efficiency = useful output E or P/input E or P times by 100, where E is Energy and P is Power.

Question 12

What equation is used to calculate current?

Answer 12

I = Q/t where Q is charge and t is time.

Question 13

What equation is used to calculate voltage?

Answer 13

V = E/Q where E is energy and Q is charge.

Question 14

What equation is used for Ohm’s Law?

Answer 14

V = IR where I is current and R is resistance.

Question 15

What equation is used for resistivity?

Answer 15

ρ = RA/L where R is resistance, A is area and L is length.

Question 16

What equation is used to calculate resistors in series?

Answer 16

Rtot = R1 + R2+ … where R1/R2 are resistors in the circuit.

Question 17

What equation is used to calculate resistance in parallel?

Answer 17

1/Rtot = 1/R1 + 1/R2 +… where R1/R2 are resistors in the circuit.

Question 18

What equation in Electricity is used to calculate power?

Answer 18

P = VI where V is voltage and I is current. Or if resistors are in series, then the equation P = I2R = V2 over R where I is current squared, R is resistance, and V is voltage which is squared.

Question 19

What equation is used to calculate emf?

Answer 19

V = E/Q where E is energy and Q is charge.

Question 20

What equation is used to calculate internal voltage

Answer 20

V = IR + Ir = I(R + r) where I is current, IR is the voltage of circuit and Ir is the V lost in battery.

Question 21

What equation is used to calculate drift velocity?

Answer 21

I = Anev where A is area of wire, n is number density, e is charge, v is drift velocity.

Question 22

What equation is used to calculate Rest energy?

Answer 22

E = mc2 where m is mass and c is speed of light squared.

Question 23

What equation is used to calculate E of photons?

Answer 23

E of photons = Rest E + Kinetic E.

Question 24

What is the simplified way for calculating E of photons?

Answer 24

2(HF) = 2mc2 + 2(1/2mv2)