An occupant of a car has a chance of surviving a crash if the deceleration during the crash is not more then 30 g. calculate the force on a 70k g decelerating at this rate

20,850 N

Explanation:

We can solve the problem by using second Newton's Law:

where

F is the force

m is the mass

a is the acceleration

In this problem, we have:

m = 70 kg is the mass

is the acceleration (which is negative, because it is a deceleration)

So, we can use the equation above to find the force:

and the negative sign simply means that the force is in the opposite direction to the motion.

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.

d) physical means can be used to separate the components of air.