Download Review - MrSherred

Mr. Sherred
Name
Physics
Date
Review for Quiz on Momentum, Specific Heat and Electronics.
What is the variable for momentum?
The symbol for momentum is a lower case p.
If an object at a mass of 5 kg and at a velocity of 5 m/s how much momentum is there?
p
m = 5 kg
v = 5 m/s
p= mv= 5*5=
= 25 kg m/s
p = 25 kg m/s
The current flowing through an electrical circuit is 101 Amps. If the voltage in the same
circuit is 188 V, what is the power of the circuit?
I = 101 A
P = IV = 101*188
P = 18988 W
P
V = 188 V
=18988 W
What is the unit for power?
The unit for power is Watts.
What is the momentum of a car going at a velocity of 5m/s with a mass of 10kg?
v = 5 m/s
p = mv = 10*5 =
p = 50 kg m/s
p
m = 10 kg
50 kg m/s
A 8,200 Watt electric washing machine operates with a current of 20 Amps what was the
voltage in the circuit?
P = 8200 W
V = P/I = 8200/20
V = 410 V
V
I = 20 A
= 410 V
The current running through computer is 100 Amps. If the voltage is 50 V, what is the
power of the circuit?
I = 100 A
P = IV
P = 5000 W
P
V = 50 V
=100*50= 5000 W
If the current of a pencil sharpener is 30 Amps and the voltage is 20 V, what is the
power?
a) 600 W
b) 1 ½ W
c) 50 W
d) 10 W
What is the equation for specific heat?
a) Q=mc∆t
b) m=t/Q
c) Q=mc/t
d) Q=m/t∆c
What type of circuit is shown below?
The circuit shown below is a parallel circuit.
A CD player uses 85 joules of energy per second. If the voltage in the CD player is the
CD player is 170 V, what amount of current is required for the operation of player?
P = 85 W
I = P/V = 85/170 =
I = .5 A
I
V = 170 V
.5 A
The specific heat of gold is 129J/kg°C. If 129 Joules of heat is added to a 2 kg mass of
gold what is the change in temperature?
ΔT
c = 129 J/kg°C
ΔT = Q/ (mc)
ΔT = .5 °C
m = 2 kg
= 129 / (2*129)
Q = 129 J
= .5 °C
What product calculates momentum?
A) Mass & Velocity
B) Time & Current
C) Mass & Time
D) Velocity & Current
What kind quantity is momentum?
A) Scalar
B) Vector
C) Mass
D) Both A&B
What are the equations that represent P?
A) d=vxt & p=vxt & I=txv
B) p= vxm
C) p=w/∆t & P=IV
D) None of the above
The specific heat of wood is 2,500 J/kg°C. It is heated from 32°C to 64°C and has a mass
of 9 kg. How much heat is required?
c = 2500 J/kg°C
Q = mc ΔT
Q = 720000 J
Q
ΔT = 64 –32 = 32°C = 9*2500*32
m = 9 kg
= 720000 J
You use your 50-watt iPod Touch to play your favorite songs. If the iPod Touch uses
100,000 joules of energy to play the music, what is the playing time of the music?
P = 50 W
Δt = W/P
Δt = 2000 s
Δt
W = 100,000 J
= 100,000/50
= 2000 s
In order to solve for Power you need to know what details about the object?
a.) Work and Voltage
b.) Mass and Velocity
c.) Work and Change in Time
d.) Current and Mass
What is the unit for Momentum?
A. m/s
B. m
C. kg
D. kg m/s
What are the two formulas used to find power?
P = IV
P = W/ Δt
If there is a TV using 400,000 joules of energy and is on for 2 hours what is the power
being used by this TV? P= W / T = 400000/ (2*3600) = 55.5 W
If you have a series circuit with a total resistance of 6Ω and 3V what is the current?
R = 6Ω
I = V/R = 3/6 = .5 A I = .5 A
I
V=3V