Answer:
The charge in each ball will be 3 * 10^-12 C
Explanation:
(Assuming the correct charge of the second ball is 8 * 10^-12)
When the balls are brought in contact, all the charges are split evenly among then.
So first we need to find the total charge combined:
(-3 * 10^-12) + (8 * 10^-12) + (4 * 10^-12) = 9 * 10^-12 C
Then, when the balls are separated, each ball will have one third of the total charge, so in the end they will have the same charge:
(9 * 10^-12) / 3 = 3 * 10^-12 C
So the charge in each ball will be 3 * 10^-12 C
Answer:
h = 51020.40 meters
Explanation:
Speed of the rifle, v = 1000 m/s
Let h is the height gained by the bullet. It can be calculated using the conservation of energy as :


h = 51020.40 meters
So, the bullet will get up to a height of 51020.40 meters. Hence, this is the required solution.
Answer:
The correct option is C
Explanation:
From the question we are told that
The initial speed of the rocket is 
The speed of the rocket engine sound is 
The final speed of the rocket is 
The speed of the sound at
would still remain V this because the speed of sound wave is constant and is not dependent on the speed of the observer(The mountain ) or the speed of the source (The rocket ).
A clear example when lightning strikes you will first see (that is because it travels at the speed of light which is greater than the speed of sound) but it would take some time before you hear the sound of the
lightning
Here we see that the speed of the lightning(speed of sound) does not affect the speed of the sound it generates
Answer:
Commutator is a ring which reverse the direction of current in AC circuit so that the coil connected to it will continuous to move in the same direction.
Explanation:
In motors there exist a coil which is rotated due to torque of magnetic field when current flow through it. Since AC current is used to run the motor so we know that AC current changes its direction after half cycle.
So here commutator plays an important role to reverse the direction of current after every half cycle so that the current goes in same direction always into the coil.
This will produce a constant direction torque on the coil so that it will rotate in same sense always.
So commutator role is to provide same direction current to the coil by reversing its direction after every half cycle
Answer:
Explanation:
Component of force perpendicular to stick
= F Sin 60°
=√3 / 2 F.
Taking torque about the other end
= √3 / 2 F x 1 Nm
Weight of stick = 60 gm
= 60 x 10⁻³ kg
= 60 x 10⁻³ x 9.8 N
= .588 N
This weight will act from the middle point of stick so torque about the
other end
= .588 x 1 Nm
Balancing these two torques we have
.588 = √3 /2 F

F = 0.679 N