Electromagnetism 1
A particle with a charge of 2μC is moving at 3 m/s perpendicularly through a magnetic field with a strength of 0.05T.
Identify (q) and (B)
q = 2μC
B = 0.05T
Rearrange the formula to make (T) the subject.
V = 2 π r /T
T = 2 π r / v
Find the force acting on OBJECT A on Earth given its mass is 30kg.
F = m x a
F = 30 x 9.8
F = 294 N
An electron gun has parallel plates separated by 4.00 cm and gives electrons 25.0 kV of energy.
What is the electric field strength between the plates?
E = V/d
E = 25 000/0.04
E = 625 000 V/m
Describe escape velocity.
The velocity that is sufficient for a body to escape from a gravitational centre of attraction without undergoing any further acceleration.
Two large parallel metal plates are 5.0 cm apart. The magnitude of the electric field between them is
800. N/C.
What work is done when one electron is moved from the positive to the negative plate?
W = V x q
W = Vq
W = 40 x (1.6 x 10^-19)
W = 6.4 x 10 ^-18 JOULES
A projectile was launched and had a range of 130 metres and was in the air for 15 seconds.
Find the horizontal velocity.
Vx = distance/time
Vx = 130 / 15
Vx = 9 m/s (horizontal
Fq = v x B
Make (B) the subject
B = E/v
Two plates are 0.14m apart and have a potential difference of 28V.
If a positive 2 nC charge were to be inserted anywhere between the plates, it would experience a force.
Calculate the force experienced by the charge.
F = qE
= (2 x 10–9 C) (200 N/C)
= 4.0 x 10-7 newtons
Place in order of altitude.
GEO Geostationary Satellite
LEO
MEO
LEO Low Earth Orbit Satellite
Altitude – 1000 km
MEO Medium Earth Orbit Satellite
Altitude – 10 000 km
GEO Geostationary Satellite
Altitude - 35 800 km
Complete the missing words.
Electric current is the flow of E____________.
A magnetic field is produced around the C_______
Charged particles moving within a magnetic field will experience a ________
Electric charge
Charge
Force
A 4.0 kg object is traveling in uniform circular motion of radius 2.0m. The magnitude of its velocity, its speed, is 15 m/s.
Calculate its ORBITAL PERIOD
T = 2 π r / v
T = 2 x π x 2 / 15
T = 0.83 seconds
A satellite in circular orbit at a distance r from the centre of Earth has an orbital velocity v.
If the distance was increased to 4r, what would be the satellite’s orbital velocity?
v = 1√4r
v = ½
Complete the missing words.
•If two parallel two conductors carry current in the SAME direction then the force is A_________.
•If two parallel conductors carry current in DIFFERENT directions then the force is ___________.
Attractive
Repulsive
A satellite is launched into space at an altitude of 1800 km. Given the Earths radius is 6380km calculate the
Calculate its ORBITAL PERIOD
T = 2 π √ r3 / GM
T = 2 x π √ (818 00 003) /
(1.67 x 10^-11)(6 x 10^24
A South Pole Station sits at a point. Assume the Earths magnetic field is 5 x 10^-5 T now determine the
The Magnetic FORCE acting on a 5m length of wire carrying a current of 5A running at an angle of 45 degrees.
F = l I B Sin Ꝋ
F = 5m x 5A x (5 x 10^-5) Sin 45
F = 8.8 x 10^-4 Newtons
A projectile was launched and had a range of 130 metres and was in the air for 15 seconds.
If it had a horizontal velocity of 9m/s then find the height reached by the projectile.
S = vt – ½ at2
S = 9(15) – ½ (9.8)(15)2
S = 135 – 1102.5
S = -967.5 m 967.5 m down
Calculate the potential energy
of a 200 kg mass orbiting around the earth in an orbit of height 100 km from the surface of earth.
EU = mgh
EU = (200)(9.8)(6500 000)
EU = 1.27 x 1010 J
A South Pole Station sits at a point. Assume the Earths magnetic field is 5 x 10^-5 T now determine the
The Magnetic FORCE acting on a 5m length of wire carrying a current of 6A running at an angle of 35 degrees
F = l I B Sin Ꝋ
F = 5m x 6 x 5 x 10^-5 Sin 35
Calculate the (i) kinetic energy
of a 200kg mass orbiting around the earth in an orbit of height 100 km from the surface of earth.
FIRST FIND THE VELOCITY using
v = square root GM/r
v = square root GM/r
v = (6.67 x 10^-11)(200)/7400 000
v =1.8 x 10^-15
Ek = ½ mv2
Ek = ½ (200)(1.8 x 10^-15)2
Ek =3.24 x 10-28 J
A particle with a charge of 2μC is moving at 3⋅106m/s perpendicularly through a magnetic field with a strength of 0.05T.
What is the magnitude of the force on the particle?
F=qvBsinθ
F=(2 x 10^-3)(3.106)(0.05)sin 90
F = 0.3 N
A ball is attached to a string that is 1.5m long. It is spun so that it completes two full rotations every second. The velocity is 18.84 m/s.
What is the centripetal acceleration felt by the ball?
FIRST FIND THE CIRCUMFERENCE (DISTANCE) of the ball.
a = v2 / r
C = 2 x pi x r
C = 2 x pi x 1.5
C = 9.42 m
a = v2 / r
a = 18.842 / 1.5
a = 237 m/s/s
A proton traveling at 1∗10^7 m/s in a horizontal plane passes through an opening into a mass spectrometer with a uniform 3T magnetic field directed upward.
The particle then moves in a circular path through and crashes into the wall of the spectrometer adjacent to the entrance opening. How far down from the entrance is the proton when it crashes into the wall?
The proton’s mass is 1.67∗10^27 kg and its electric charge is 1.6∗10^-19C.
qvB=mv /r2
r =mv/qvB
34.8 x 2
69.6 mm
A piece of wire with a length of 8cm wire and a current of 2A is oriented 36o from a magnetic field with a strength of 6T.
What is the force on the wire
F=ILBsinθ
F=(2A)(0.08m)(6T)sin(36)
F=0.564N
A projectile was launched and had a range of 140 metres and was in the air for 8 seconds.
At what angle to the horizontal was it launched?
Given the horizontal initial velocity is 17.5 m/s.
FIRST FIND THE VERTICAL VELOCITY
S = Uyt + 1/2 a t2
0 = Uy(8) + ½ (9.8)(8)2
Uy = 4.9 (64) /8 = 39.2 m/s
Tan Ꝋ = O/H
17.5 /39.2 Shift Tan
24°