Formulas Flashcards
How to find density ?
density= mass/ volume
How to find speed and average speed
Speed = Distance/ Time
Average speed= Total distance travelled / Total time taken
how to find acceleration
Acceleration= Change in velocity/ Change in time
How to find centripetal acceleration (the rate of motion of an object inwards towards the center of a circle.)
a(c) = v^2/r
a(c) = centripetal acceleration
v = velocity
r = radius
how do you find weight
weight = mass x gravity
what is the formula for force?
F = ma
how do you find the spring constant
k = f/x
k= spring constant
f = force
x = the extension
what is the formula for the moment of a force ?
Moment of a force = Force × Perpendicular distance from the pivot
what is the formula for impulse
Impulse = Force x Time
what are the two equations to find the change in momentum
- Δp = m Δv
where,
Δp is the change in momentum,
m is the mass of object,
Δv is the change in velocity of object.
- Δp = F Δt
where,
Δp is the change in momentum,
F is the force applied on the body,
Δt is the time interval for which force acts on the object.
how to calculate resultant force ?
Resultant force = Change in momentum / Change in time
how to find the kinetic energy
Kinetic energy= 0.5 m v^2
what is the formula for potential energy
Potential energy = mgh
m= mass
g= gravity
h= height
what is the formula for work
Work = Force x Distance travelled in the direction of the force
w=fd in short
how to calculate percentage efficiency ?
Percentage efficiency = [ Useful energy output / Total energy input] x 100
OR
Percentage efficiency = [ Useful power output / Total power input] x 100
WHAT ARE THE TWO FORMULAS FOR POWER ?>!>?#l!p@#l!
Power= Work done / Time taken
Power= Energy transferred / Time taken
what is pressure ? (TWO FORMULAS !!)
Pressure = Force / Area
Pressure = Height x Density x gravitational field strength
how to calculate change in thermal energy
change in thermal energy = mass x specific heat capacity x temperature change
what is the wave equation mamacitas ؟
Wave Equation :
velocity = frequency x wavelength
how to find the refractive index when “i” and “r” are known ?
Refractive Index (n)= Sin(i)/Sin(r)
how to find the refractive index when the critical angle is known ?
Refractive Index (n) = 1/Sin(c)
what is the value of the speed of light ?
peed of light : 3.0 × 10^8m/s
the value of Human Audio Frequency?
the value of Human Audio Frequency : 20 Hz to 20 000 Hz
the value of speed of sound in air?
the value of speed of sound in air : 330–350 m/s
how to find electric current
I = Q/T
i = current (in amps)
q = the charge (in coulombs)
t = time (in seconds)
how to find voltage (two formulas)
- Voltage (V) = energy transferred (J) / charge (C)
V = E/Q
- Voltage (V) = current (A) × resistance (Ω)
V = IR
what are the two formulas for power
- Power (W) = current (A) × voltage (V)
P = IV
- Power (W) = current^2 (A) × resistance (Ω)
P = I^2R
give me the two formulas for energy transferred
- Energy transferred (J) = current (A) × voltage (V) × time (s)
ΔE = IVt
- Energy transferred (J) = power (W) × time (s)
ΔE = Pt
how to calculate the resistance
Resistance (Ω) = resistivity (Ωm) × length (m) area (m^2)
Note: since wires have a circular cross section, area = π × radius^2
OR
R = V/I (Volts divided by amps)
formula for transformers ? (two)
Transformers:
1. voltage in secondary coil/voltage in primary coil = current in secondary coil/current in primary coil
- voltage in primary coil/voltage in secondary coil = current in secondary coil/current in primary coil
