Apartially evacuated airtight container has a tight-fitting lid of surface area 79.9 cm2 and negligible mass. if the force required to remove the lid is 388 n and the atmospheric pressure is 1.00 × 105 pa, what is the air pressure in the container before it is opened?

Explanation:

As we know that the air container is fixed by the lid on it and it is removed by external force

F = 388 N

now this external force must be same as the force due to pressure difference of the object

so it is given as

here we know that

here we have

now pressure is given as

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

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.