Sound travels through all mediums solid, liquid, and gas. Because sound is a vibration it will travel fastest through solids. This is because the vibrations that make up sound are carried from one place to another by neighboring molecules vibrating against one another. The density of the solid is higher than liquid and gas which means the molecules are more tightly packed and the vibration can pass from one to the next more quickly.
Kinetic energy<span> increases with the square of the velocity (KE=1/2*m*v^2). If the velocity is doubled, the KE quadruples. Therefore, the </span>stopping distance<span> should increase by a factor of four, assuming that the driver is </span>can<span> apply the brakes with sufficient precision to almost lock the brakes.</span>
C) The longer the line, the greater the magnitude of the vector. As for the direction, just think of a compass.
Answer:
a) 
b)
c) 
d) Treat the humans as though they were points or uniform-density spheres.
Explanation:
Given:
- mass of Mars,

- radius of the Mars,

- mass of human,

a)
Gravitation force exerted by the Mars on the human body:

where:
= gravitational constant


b)
The magnitude of the gravitational force exerted by the human on Mars is equal to the force by the Mars on human.


c)
When a similar person of the same mass is standing at a distance of 4 meters:


d)
The gravitational constant is a universal value and it remains constant in the Universe and does not depends on the size of the mass.
- Yes, we have to treat Mars as spherically symmetric so that its center of mass is at its geometric center.
- Yes, we also have to ignore the effect of sun, but as asked in the question we have to calculate the gravitational force only due to one body on another specific body which does not brings sun into picture of the consideration.