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,

Principles<span> of </span>arc welding<span>. </span>Arc welding<span> is a </span>welding<span> process, in which heat is generated by an </span>electric arc<span> struck between an electrode and the work piece. </span>Electric arc<span> is luminous</span>electrical<span> discharge between two electrodes through ionized gas.</span>
The final temperature of the tea cup is 100°C.
<h3>What is internal energy?</h3>
The Internal energy is the energy of a substance due to to the constant random motion of its particles.
The symbol for internal energy of a substance is U and it is measured in Joules.
ΔU = q + W
- W is the mechanical work.
In conclusion, the final temperature of the tea cup at room temperature of 24 °C which is heated until it has twice the internal energy is 100°C.
Learn more about internal energy at: brainly.com/question/24028630
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Answer:
140°
Explanation:
The law of reflection states that the angle of redlection equals to the angle of incidence.
When light rays hit surface at 20°, they also leave the surface at the same angle
Since the whole surface has 180° then subtracting these two angles from total angle gives the the angle between the incident and reflected rays.
180°-20°-20°=140°
The angle of incidence and reflection are equal hence 140/2=70°
The question needed the angle between the incident and reflected rays which is already calculated as 140°
Explanation:
It is known that relation between force and acceleration is as follows.
F =
I is given that, mass is 1090 kg and acceleration is 21 m/s. Therefore, we will calculate force as follows.
F =
=
= 1430.625 N
Also, it is known that
= 7.70 degrees
Thus, we can conclude that the maximum steepness for the car to still be able to accelerate is 7.70 degrees.