Answer:
1)
is<u> positive.</u>
<u></u>
2) 
Explanation:
<h2><u>
Part 1:</u></h2>
<u></u>
The charged rod is held above the balloon and the weight of the balloon acts in downwards direction. To balance the weight of the balloon, the force on the balloon due to the rod must be directed along the upwards direction, which is only possible when the rod exerts an attractive force on the balloon and the electrostatic force on the balloon due to the rod is attractive when the polarities of the charge on the two are different.
Thus, In order for this to occur, the polarity of charge on the rod must be positive, i.e.,
is <u>positive.</u>
<u></u>
<h2><u>
Part 2:</u></h2>
<u></u>
<u>Given:</u>
- Mass of the balloon, m = 0.00275 kg.
- Charge on the balloon,

- Distance between the rod and the balloon, d = 0.0640 m.
- Acceleration due to gravity,

In order to balloon to be float in air, the weight of the balloom must be balanced with the electrostatic force on the balloon due to rod.
Weight of the balloon, 
The magnitude of the electrostatic force on the balloon due to the rod is given by

is the Coulomb's constant.
For the elecric force and the weight to be balanced,

Answer:
<h2>2.35 N</h2>
Explanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question
force = 0.49 × 4.8 = 2.352
We have the final answer as
<h3>2.35 N</h3>
Hope this helps you
Acceleration is the
rate of change of velocity, a body moving with uniform velocity does not
possess acceleration at all i.e. acceleration is zero
Answer:
The magnetic field is strongest at the center and weakest between the two poles just outside the bar magnet. The magnetic field lines are densest at the center and least dense between the two poles just outside the bar magnet.
Explanation: