Answer:
(a) 1058.4 J
(b) -10584 J
Explanation:
Parameters given:
Mass of astronaut, m = 72 kg
Distance moved by astronaut, d = 15 m
(a) WORK DONE BY FORCE FROM THE HELICOPTER
Work done is given as the product of Force applied to a body and the distance moved by the body:
W = F * d
The force from the helicopter is given as:
F = m * a
where a = acceleration of the astronaut due to the helicopter
Therefore, the work done is given as:
W = m * a * d
W = 72 * g/10 * 15
W = 
W = 1058.4 J
(b) WORK DONE BY FORCE OF GRAVITY
W = F * d
The force of gravity is given as:
F = -m * g
where g = acceleration due to gravity
The negative sign is due to the fact that the astronaut moves in an opposite direction (upwards) to the force of gravity (Gravity acts downwards)
Therefore, the work done is given as:
W = -m * g * d
W = -72 * 9.8 * 15
W = -10584 J
An airplane has a large amount of kinetic energy in flight due to its large mass and fast velocity.
This concept is inferred from quantum mechanics. According to quantum mechanics, electrons can absorb or emit energy by a discrete amount of energy called quanta. This follows from the two contradicting theory of wave-particle theory of light. It was widely accepted already that light behaves like a wave. However, questions are still unanswered on why electromagnetic waves emit or absorb light in specific frequencies. Until Planck proposed his equation: E = hν, where E is the energy, h is called the Planck's constant and ν is the frequency.
In this equation, it signifies that increase energy is progressing at discrete amounts of frequencies and this constant is denoted by h.
vf=vi+at
No need for rearranging because it is already set up for Vf (final velocity)
a= -9.8m/s² (because it is falling)
vi= 0
t= 2.7
0 + -9.8(2.7) = vf
vf = -26.5 (-26.46)
