Answer:
F'= 4F/9
Explanation:
Two small objects each with a net charge of +Q exert a force of magnitude F on each other. If r is the distance between them, then the force is given by :
...(1)
Now, if one of the objects with another whose net charge is + 4Q is replaced and also the distance between +Q and +4Q charges is increased 3 times as far apart as they were. New force is given by :
.....(2)
Dividing equation (1) and (2), we get :

Hence, the correct option is (d) i.e. " 4F/9"
A) the electrode at which oxidation takes place
Answer:

Attractive
Explanation:
Data provided in the question
The potential energy of a pair of hydrogen atoms given by 
Based on the given information, the force that one atom exerts on the other is
Potential energy μ = 
Force exerted by one atom upon another

or

or

As we can see that the
comes in positive and constant which represents that the force is negative that means the force is attractive in nature
The mass of an object on Earth is the same as its mass on the Moon. The weight is different.
Weight = m * g
Weight ( Moon ) = 40 kg * 1.6 m/s² = 64 N
If the mass of an object on Earth is 40 kg, its mass on the Moon is 40 kg and its weight on the Moon is 64 N.
Answer:
4 m/s
Explanation:
m1 = m2 = m
u1 = 20 m/s, u2 = - 12 m/s
Let the speed of composite body is v after the collision.
Use the conservation of momentum
Momentum before collision = momentum after collision
m1 x u1 + m2 x u2 = (m1 + m2) x v
m x 20 - m x 12 = (m + m) x v
20 - 12 = 2 v
8 = 2 v
v = 4 m/s
Thus, the speed of teh composite body is 4 m/s.