"Sort the following objects as part of the system or not."An 80-kg quarterback jumps straight up in the air right before throwing a 0.43-kg football horizontally at 15 m/s . How fast will he be moving backward just after releasing the ball?

0.080625 m/s

Explanation:

Horizontally, the total momentum must be conserved, meaning the momentum before and after the throw must be the same.

The total momentum before the throw is 0, and so is after the throw:

mv + MV = 0

where m, M are the masses of the ball and the quarterback, respectively. v and V are the velocities of the ball and the quarterback, respectively.

0.43*15 + 80V = 0

80V = -6.45

V = -6.45 / 80 = -0.080625 m/s

So he will be moving in the opposite direction with the ball at the rate of 0.080625 m/s

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.

in physics zero. in muscle fatigue could be high