A helicopter lifts a 66 kg astronaut 15 m vertically from the ocean by means of a cable. The acceleration of the astronaut is g/
1 answer:
Answer
given,
mass of the astronaut = 66 kg
height of the lift = 15 m
acceleration = g/11 = 0.89 m/s²
a) the work done by helicopter
W = F× h
= m (a+g)h
= 66 × (9.8+0.89)15
W =10583.1 J
b) work done by the gravity
W= mgh
W = - 66 × 9.8 × 15
W = -9702 J
c) Δ KE = net work done
Δ KE = 10583.1 - 9702
Δ KE = 881.1 J
d) speed
v =5.17 m/s
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Answer:
c. There is a buoyant force that is proportional to the volume of your body that is below the level of the water.
Explanation:
Buoyancy can be defined as a force which is created by the water displaced by an object.
Simply stated, buoyancy is directly proportional to the amount of water that is being displaced by an object.
Hence, the greater the amount of water an object displaces; the greater is the force of buoyancy pushing the object up.
The buoyancy of an object is given by the formula;
Where;
Fb = buoyant force of a liquid acting on an object.
g = acceleration due to gravity.
p = density of the liquid.
v = volume of the liquid displaced.
h = height of liquid (water) displaced by an object.
A = surface area of the floating object.
The unit of measurement for buoyancy is Newton (N).
In this scenario, you are standing on the bottom of a lake with your torso above water. Thus, there is a buoyant force that is proportional to the volume of your body that is below the level of the water.