29.

 

 

 

 

Therefore, the net gravitational force
on the rocket from the earth and the moon is 4.48 N.

 

30.

a)

 

 
 

 

 

=  m

Therefore, the meteor is  above the earth’s surface.

 

b)

 

  

 

Therefore, the 30kg meteor will
experience a force of 216 N at the same altitude as the 12kg meteor.

 

 

 

31.

a)

 

 
 

 

Therefore, the radius of the circular
orbit is m.

 

b)

 

 
 

 

Therefore, the speed of the satellite
is 6996 m/s.

 

c)

 

 

 

Therefore, the period of the orbit is s which is approximately 2 hours.

 

32.

  

 

 

 N

Therefore, the bathroom scale will give a reading of 450N.

33.

a)

 

 

  

 

  

 

 

  

 

Therefore, the net force on charge 1 is 1.91 N N 45o E

 

b)

 

  

 

 

  

Therefore, the total electric field  acting on charge 1 is 1.91 N/C N 45o
E

 

34.

a)

The sphere is at rest so it has a net force of 0.

 

 

 

 

Therefore, the tension in the thread
is 1.92N.

 

 

 

 

 

 

b)

  

 

 

 

 

   

The charge on 2 is. The charge is positive on 2 because
it attracts 1, which holds a negative charge.

 

35.

a)

 

 

 

 

Therefore, the acceleration of the
electron between the plates is .

 

b)

 
 

 

 

 

 

  

  

  

Therefore, the horizontal distance
travelled by the electron when it hits the plate is 9.6 cm.

 

 

c)

 

 

 
m/s

Therefore, the velocity of the
electron as it strikes the plate is m/s.

 

 

 

36.

a)

 

 

 

Therefore,
the total electric potential energy is -405 J.

 

b)

 

 

 

Therefore, the total electric
potential at point Z is

 

 

 

 

 

 

 

37.

 

 

  

 

 

 

 

 

 

 

 

 

  

 

Therefore, the minimum distance
between the two pucks is 24.3m.

 

38.

a)

The sphere has a positive charge
because the electric force must act upward in order to cancel out the force of
gravity which acts downwards. For the electric force to be directed up on the
sphere, it must be attracted to the top negative plate which means that the
sphere must be positive.

 

 

 

 

 

 

 

b)

 

 

 

 

 

Therefore, the magnitude of the charge
on the sphere is.

 

c)

 

 

 

Therefore, the sphere has a deficit of
three electrons.

 

39.

a)

 

 

 south

Therefore, the initial magnetic force was
.

 

 

 

 

 

 

 

 

 

b)

 

  

 

 

 

Therefore, the electron will
experience uniform circular motion in a circle with a radius of 1.42 mm.

 

 

 

40.

a)

 

 

 
down      (right hand rule used
to find direction)

 

Therefore, the magnetic force on the
wire is 11.2 N down

 

 

 

 

b)

i.              If the wire is rotated slightly in
the horizontal plane, the angle between the current and magnetic force will not
be 90° anymore which will cause the magnetic force to decrease.

 

ii.             If the current is doubled, the
force will be doubled because the magnetic force is directly proportional to
the current.

 

iii.            If the magnetic field is reversed
the magnetic force will also be reversed. The magnetic force will point upward
instead of down.

 

 

 

41.

a)

The particle accelerator uses powerful
electromagnets to curve the path of the particles into a circle. Oppositely
charged accelerating cavities speed up the particles. The powerful magnets are
positioned in a circular pattern with the accelerating cavities between them.
In order to counteract the increased radius of curvature when accelerating
particles increase in velocity, the strength of the magnetic field is increased
to cause a greater magnetic force. Energy is continuously added into the charged
particle as it continues to move around the circuit. As the speed of the
charged particles increases, the charges in the cavities are switched more
quickly.

 

b)

If the magnetic field was too weak,
the particles would eventually collide with the walls of the drift tubes or
accelerator. This is because the radius of the curvature increases as the
particles accelerate.

 

c)

Electric fields must be continuously
increased as the particle picks up speed so the particle can gain more energy
and travel faster. The strength of the magnetic field is increased to cause a
greater magnetic force in order to counteract the increased radius of curvature
caused by the accelerating particles.