NB: The diagram of the pulley system is not shown but the information provided is sufficient to answer the question
Answer:
Power = 2702.56 W
Explanation:
Let the power consumed be P
Energy expended = E = mgh
height, h = 5 m
E = 80 * 9.8 * 5
E = 3920 J

To calculate the time, t
From F = ma
F = 900 N
900 = 80 a
a = 900/80
a = 11.25 m/s²
From the equation of motion, 
The drill head starts from rest, u = 0 m/s

Power, P = E/t
P = 3920/0.0.943
P = 4157.79 W
But Efficiency, E = 0.65
P = 0.65 * 4157.79
Power = 2702.56 W
Answer:
497.00977 N
3742514.97005
Explanation:
= Density of water = 1000 kg/m³
C = Drag coefficient = 0.09
v = Velocity of dolphin = 7.5 m/s
r = Radius of bottlenose dolphin = 0.5/2 = 0.25 m
A = Area
Drag force

The drag force on the dolphin's nose is 497.00977 N
at 20°C
= Dynamic viscosity = 
Reynold's Number

The Reynolds number is 3742514.97005
Answer:
22.5J
Explanation:
Here the force is given. Also, the displacement is given as 30cm.
First we should check if all the values are in their standard form.
Here 30cm should be converted to metre by dividing it with 100.
Which would give us 0.3m
Now we use the equation W=force x displacement =75 x 0.3=22.5J
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