Answer:
by reducing friction.....
Answer: C
The gravity acceleration is in the same direction as the force of gravity, and thus toward the center of the earth.
Explanation:
All celestial bodies in our solar system experience forces between each other. On earth, the localized gravitational force in the earth's atmosphere is directed toward the center of the earth. It's magnitude is
32.174 ft/s² in English units,
9.807 m/s² in SI units.
All objects that have mass are subject to the earth's gravitational acceleration. The product of mass and the earth's gravitational acceleration defines the weight of an object as its gravitational force.
E the temperature of a substance. Water has a very high specific heat. That means it needs to absorb a lot of energy before its temperature changes. Sand , on the other hand, have lower specific heats. This means that their temperatures change more quickly. When the summer sun shines down on them, they quickly become hot.
The magnetic force experienced by the proton is given by

where q is the proton charge, v its velocity, B the magnitude of the magnetic field and

the angle between the direction of v and B. Since the proton moves perpendicularly to the magnetic field, this angle is 90 degrees, so

and we can ignore it in the formula.
For Netwon's second law, the force is also equal to the proton mass times its acceleration:

So we have

from which we can find the magnitude of the field: