Answer:
.
Explanation:
When the ball is placed in this pool of water, part of the ball would be beneath the surface of the pool. The volume of the water that this ball displaced is equal to the volume of the ball that is beneath the water surface.
The buoyancy force on this ball would be equal in magnitude to the weight of water that this ball has displaced.
Let
denote the mass of this ball. Let
denote the mass of water that this ball has displaced.
Let
denote the gravitational field strength. The weight of this ball would be
. Likewise, the weight of water displaced would be
.
For this ball to stay afloat, the buoyancy force on this ball should be greater than or equal to the weight of this ball. In other words:
.
At the same time, buoyancy is equal in magnitude the the weight of water displaced. Thus:
.
Therefore:
.
.
In other words, the mass of water that this ball displaced should be greater than or equal to the mass of of the ball. Let
denote the density of water. The volume of water that this ball should displace would be:
.
Given that
while
:
.
In other words, for this ball to stay afloat, at least
of the volume of this ball should be under water. Therefore, the volume of this ball should be at least
.
Answer:
211 mmHg
Explanation:
Absolute Pressure = Gauge Pressure + Atmospheric pressure
128 = Gauge Pressure + 100
Gauge Pressure = 28 KPa = 28 × 10³ Pa
Also Gauge Pressure = ρgh
ρ = density = 13550 kg/m³
g = acceleration due to gravity = 9.8 m/s²
h = pressure head = ?
28 × 10³ = 13550 × 9.8 × h
h = 28000/(13550 × 9.8)
h = 0.211 m = 211 mm
The work done on the backpack by the student applies 80 N of force to lift the backpack 1.5 m is 120J.
<h3>How to calculate work done?</h3>
Work done is a measure of energy expended in moving an object; most commonly, force times distance.
It is said that no work is done if the object does not move, hence, the work done on an object can be calculated as follows:
Work done = Force × Distance
According to this question, a student carries a very heavy backpack and to lift the backpack off the ground, the student must apply 80 N of force to lift the backpack 1.5 m.
Work done = 80N × 1.5m
Work done = 120J
Therefore, the work done on the backpack by the student applies 80 N of force to lift the backpack 1.5 m is 120J.
Learn more about work done at: brainly.com/question/28172139
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Answer:
The back end of the vessel will pass the pier at 4.83 m/s
Explanation:
This is purely a kinetics question (assuming we're ignoring drag and other forces) so the weight of the boat doesn't matter. We're given:
Δd = 315.5 m
vi = 2.10 m/s
a = 0.03 m/s^2
vf = ?
The kinetics equation that incorporates all these variables is:
vf^2 = vi^2 + 2aΔd
vf = √(2.1^2 + 2(0.03)(315.5))
vf = 4.83 m/s