Answer: a) the force will be repulsive
b) the ratio of the new force to the old force will be 2
c) O
Explanation:
a) since charge -Q is moved from A to B, this implies that sphere A is negatively charged. The two spheres are now negatively charged and will repel themselves.
b) initial force will be -q(-Q)/d2
Adding extra charge -Q will cause change on B to become -2Q
The new force will be - 2Q(-q)/d2
Dividing new force by old force will give 2
C) if B is neutralized, the net charge becomes 0 and there will be no force on it.
Answer:
1.38*10^18 kg
Explanation:
According to the Newton's law of universal gravitation:

where:
G= Gravitational constant (6.674×10−11 N · (m/kg)2)
ma= mass of the astronaut
mp= mass of the planet

so:

Explanation:
Food chain is linear sequence of the organisms through which the nutrients and the energy pass as one organism eats the another.
<u>If one species in the food chain ceases to exist, the other members in rest of chain could cease to exist too or may increase in population which can affect other food chains. (Breaking of food chain).</u>
This is because the animals in the food chain are dependent on the nutrient present in the another.
For example in the food chain,
Grass ---- Deer ------ Lion
If all deer extinct, the lion will die as they will have nothing to feed on and the population of grass increases.
Answer:
1362000 kgm/s
Explanation:
So the total mass combination of the plane and the people inside it is
M = 35000 + 160*65 = 45400 kg
After 15 seconds at an acceleration of 2 m/s2, the plane speed would be
V = 2*15 = 30 m/s
So the magnitude of the plane 15s after brakes are released is
MV = 45400 * 30 = 1362000 kgm/s
If net external force acting on the system is zero, momentum is conserved. That means, initial and final momentum are same → total momentum of the system is zero.