The force will remain same if the mass of each sphere is doubled and the distance between them is doubled as well.
The force of gravitation between two spheres is given by
m1= mass of first object
m2= mass of second object
r= distance between the masses
Now if each mass is doubled and the distance r is doubled as well
F'=
so F'= F
so the force remains same and is equal to 1000 N.
Answer:
a) 3.43 m/s
Explanation:
Due to the law of conservation of momentum, the total momentum of the bullet - rifle system must be conserved.
The total momentum before the bullet is shot is zero, because they are both at rest, so:
Instead the total momentum of the system after the shot is:
where:
m = 0.006 kg is the mass of the bullet
M = 1.4 kg is the mass of the rifle
v = 800 m/s is the velocity of the bullet
V is the recoil velocity of the rifle
The total momentum is conserved, therefore we can write:
Which means:
Solving for V, we can find the recoil velocity of the rifle:
where the negative sign indicates that the velocity is opposite to direction of the bullet: so the recoil speed is
a) 3.43 m/s