Question

98 POINTS, 5 simple questions!! HELP

Answer 1

This is a fun question - your science teacher is creative!

First is easy, 25000 feet converts to 7620 meters

Potential energy is a product of mass, gravity and height. In this case, mass is 90Kg and height is 7620m. gravity on earth is 9.8m/s2.

Potential energy = 90(9.8)(7620) = 6720840J

By Newton 2nd law, force is equal to mass times acceleration.

Gravity force = mass*gravity

= 90(9.8) = 882N

Acceleration when he leaves the plane is gravity, 9.8m/s2

With no wind resistance, the acceleration is constant at 9.8.

Using kinematic equation, v2 = u2 + 2as where u is initial velocity, v is final velocity, a is acceleration and s is distance traveled.

In this case, u=0, a=9.8, s=7620

v^2 = 2(9.8)(762) = 149352

final velocity = sqrt (149352) = 386.5m/s

Answer 2

25,000 Feet = 7620m

PE = mgh where m is mass, g is gravity accel: 9.8 n h is height

= 90 x 9.8 x 7620

= 6720840J

= 6.72MJ

F = ma where m is mass, a is accel = gravity = 9.8

= 90 x 9.8

= 882N

Accel = gravity = 9.8m/s^2

KE = 1/2mv^2 where m is mass n v is vel

if no wind resistance, PE leaving airplane = KE at net

6720840 = 1/2 x 90 x v^2

v^2 = 149352

v = 386.5m/s