Abaseball is thrown straight downward with an initial speed of 40 ft=s from the top of the washington monu- ment (555 ft high). how long does it take to reach the ground, and with what speed does the baseball strike the ground?

4.53 second, 195 ft/s

Explanation:

u = 50 ft/s

h = 555 ft

g = 32 ft/s^2

Let the time taken by the ball to reach the ground is t and the velocity of the ball as it hits the ground is v.

Use third equation of motion

v = 195 ft /s

Thus, the ball strikes the ground with velocity 195 ft/s.

Use first equation of motion

v = u + at

195 = 50 + 32 t

32 t = 145

t = 4.53 second

Thus, the ball reach the ground in 4.53 second.

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.