An atom is defined as having the same number of electrons (negative charge), protons (positive charge) and neutrons (no charge). This means that it will have the same amount of negative and positive charge, giving it a net zero charge. On the other hand, an ion has different amount of electrons and protons.
Answer:
The gravity on this planet is stronger than that of earth.
Explanation:
First we need to find the acceleration due to gravity value of this planet to compare its gravity force with that of the earth. Hence, we will use second equation of motion:
h = Vi t + (0.5)gt²
where,
h = height or depth of crater = 100 m
Vi = Initial Velocity of rock = 0 m/s
t = time = 4 s
g = acceleration due to gravity on this planet = ?
Therefore,
100 m = (0 m/s)(4 s) + (0.5)(g)(4 s)²
g = (200 m)/(16 s²)
g = 12.5 m/s²
on earth:
ge = 9.8 m/s²
Since,
ge < g
Therefore,
<u>The gravity on this planet is stronger than that of earth.</u>
The impulse required to decrease the speed of the boat is equal to the variation of momentum of the boat:

where
m=225 kg is the mass of the boat

is the variation of velocity of the boat
By substituting the numbers into the first equation, we find the impulse:

and the negative sign means the direction of the impulse is against the direction of motion of the boat.
Choice - B is the correct one.
At the top of the arc, at one end of the swing:
-- it's not going to get any higher, so the potential energy is maximum
-- it stops moving for an instant, so the kinetic energy is zero
At the bottom of the arc, in the center of the swing:
-- it's not going to get any lower, so the potential energy is minimum
-- it's not going to move any faster, so the kinetic energy is maximum