Answer:
The value is 
Explanation:
The radius is 
The mass of the ordinary matter is 
Generally the speed of the star is mathematically represented as

Here G is the gravitational constant with a value

So

=> 
Answer:
I think it's A but I'm not sure
Answer:
Figure A
Explanation:
At first, the inflated balloon is rubbed against the hair.
In this situation, the balloon is charged by friction: because of the friction between the surface of the balllon and the hair, electrons are transferred from the hair to the surface of the balloon.
As a result, when the balloon is detached from the hair, it will have an excess of negative charge (due to the acquired electrons).
Then, the balloon is placed in contact with the non-conducting wall.
The non-conducting wall is initially neutral (equal number of positive and negative charges).
Because the wall is made of a non-conducting material (=isolant), the charges cannot move easily through it. Therefore, even though the charges on the wall feel a force due to the presence of the electrons in the balloon, they will not redistribute along the wall.
Therefore, the charges on the wall will remain equally distributed, as shown in figure A.
A geyser is actually a devise that coverts electrical energy
into heat energy for heating up water. The heating element that is inside the
geyser actually gets heated up and then in turn it heats the water in contact
with it within the geyser. There is also a thermostat device within the geyser
that cuts off the heating when the water temperature reaches the desired level.
This helps in stopping of electrical energy loss. One inlet brings in cold
water while another outlet gets rid of the hot water. When the temperature of
the water falls below the desired level the heating is again started by the
thermostat.