Surface tension<span> is a property of the surface of a liquid that allows it to resist an external force. for example, some objects can float on the surface of water, even though they are denser than water, and in the ability of some insectsto run on the water surface. This property is caused by cohesion of similar molecules, and is responsible for many of the behaviors of liquids.</span>
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:
160J
Explanation:
Given parameters:
Frequency = 16Hz
Wavelength = 10m
Unknown:
Waves speed = ?
Solution:
Waves speed is the product of frequency and wavelength;
Waves speed = fλ
f is the frequency
λ is the wavelength
Now insert the parameters and solve;
Waves speed = 16 x 10 = 160J
Answer:
PE = mgh = 13.6(9.81)(1.25) = 166.77 ≈ 167 J
Explanation:
Answer:
The first interval is walked slowly, this is a straight line with a small slope
Second interval stops, which gives a horizontal line, indicating the same position
Third interval, walk back, straight downhill
Explanation:
In this problem we have a uniform movement, this means that the acceleration in each intervals
x = v t
The first interval is walked slowly, this is a straight line with a small slope
Second interval stops, which gives a horizontal line, indicating the same position
Third interval, walk back, straight downhill