Estimate the kinetic energy necessary for a projectile with mass m can "escape" from the surface of a planet if it is launched vertically upward. express your estimation in terms of g which is the acceleration due to gravity at the planet's surface and rp which is the planet's radius. ignore air resistance.

a. the kinetic energy is about than 2mgrp.
b. the kinetic energy greater than mgrp.
c. the kinetic energy is about than 2mr2p/g.
d. the kinetic energy greater than mr2p/g.

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

What is the stall speed at sea level of an airplane that weights 10000 lbs., has a wing area of 300ft^2, and a maximum lift coefficient of 1.4? what is the stall speed if flaps that double cl,max are applied?

The energy equivalent of the rest mass of an electron is