The answer would be B..
Since sand can heat up quickly, it will also cool off quickly. But water takes a long time to heat up and cool down.
Answer:
Negative 9.8 meters per second squared
Explanation:
The negative is for the direction (down, towards the center of the earth). Often this can be estimated as -10 m/s^2 to make calculations easier.
The tension in the string corresponds to the gravitational attraction between the Sun and any planet.
This is a "trick" question.
If the elevator is traveling at constant speed, it means it is at rest. This means anything inside the elevator traveling at constant speed, weights the same as in an elevator not moving -also at rest-.
So the 100N weight's weight doesn't change in an elevator traveling at constant speed.