Answer:
The normal force the ground exerts on the block, F = -300 N
Explanation:
Given data,
The block pulled up with a tension force, T = 100 N
The weight of the block, W = 300 N
The weight of the block is due to the force of attraction of gravitation.
The surface exerts a force that is equal and opposite to the force acting on the block due to gravitation.
The weight of the block,
W = mg
300 N
The normal force the ground exerts on the block,
F = - mg
= - 300 N
Hence, the normal force the ground exerts on the block, F = -300 N
Explanation:
Newton's second law says that when a constant force acts on a massive body, it causes it to accelerate.
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
Kinetic energy, KE, is modeled by the formula

, where m is the mass in kg and v is the velocity in m/s.
In this scenario, mass and one-half are constant but the velocity changes.
You can see that by squaring twice the velocity, that is equal to four times the original KE. Therefore, the answer is 4k.