In february 1955, a paratrooper fell 370 m from an airplane without being able to open his chute but happened to land in snow, suffering only minor injuries. assume that his speed at impact was 55 m/s (terminal speed), that his mass (including gear) was 68 kg, and that the magnitude of the force on him from the snow was at the survivable limit of 1.1 × 105 n. what are (a) the minimum depth of snow that would have stopped him safely and (b) the magnitude of the impulse on him from the snow?

a) 0.94 m

The work done by the snow to decelerate the paratrooper is equal to the change in kinetic energy of the man:

where:

is the force applied by the snow

d is the displacement of the man in the snow, so it is the depth of the snow that stopped him

m = 68 kg is the man's mass

v = 0 is the final speed of the man

u = 55 m/s is the initial speed of the man (when it touches the ground)

and where the negative sign in the work is due to the fact that the force exerted by the snow on the man (upward) is opposite to the displacement of the man (downward)

Solving the equation for d, we find:

b) -3740 kg m/s

The magnitude of the impulse exerted by the snow on the man is equal to the variation of momentum of the man:

where

m = 68 kg is the mass of the man

is the change in velocity of the man

Substituting,

Decrease

Explanation:

If you were on the Moon, which has significantly less mass than the Earth, your weight would: decrease

The point that seemed to be giving me a complicated time was being able to distinguish the difference and meaning of weight and mass and being able to apply that to a problem. I kept mixing up the definitions. For example in homework 3.1, one question asked:

If you were on the moon, which has significantly less mass than the earth, your mass would:

a. increase

b. decrease

c. stay the same

d. become zero

The definition of mass is the amount of matter in an object. The definition of weight is the amount or unit of force. For me, I just had to remember that when it asked about weight, it wasn’t referring how heavy an object is. After I was able to recognize that when it came to weight, questions became easier.

The final and correct answer was decreasing. The answer is because the Moon’s mass is less. This means the gravitational force is less on your body, therefore, your mass is going to be lighter