Answer:
Force is 57.69 N to the opposite direction of motion of dolphin.
Explanation:
We have force is the product of mass and acceleration.
That is
Force = Mass x Acceleration
F = ma
Mass of dolphin, m = 30 kg
We have equation of motion, v = u + at
Final velocity, v = 7 m/s
Initial velocity, u = 12 m/s
Time, t = 2.60 s
Substituting
7 = 12 + a x 2.6
a = -1.92 m/s²
Force, F = 30 x -1.92 = -57.69 N
So the force is 57.69 N to the opposite direction of motion of dolphin.
Answer:
9.8 × 10⁴Pa
Explanation:
Given:
Velocity V₁ = 12m/s
Pressure P₁ = 3 × 10⁴ Pa
From continuity equation we have
ρA₁V₁ = ρA₂V₂
A₁V₁ = A₂V₂
making V₂ the subject of the equation;

the pipe is widened to twice its original radius,
r₂ = 2r₁
then the cross-sectional area A₂ = 4A₁
⇒ 

This implies that the water speed will drop by a factor of
because of the increase the pipe cross-sectional area.
The Bernoulli Equation;
Energy per unit volume before = Energy per unit volume after
p₁ +
ρV₁² + ρgh₁ = p₂ +
ρV₂² + ρgh₂
Total pressure is constant and
= P =
ρV₂²ρV²
p₁ +
ρV₁² = p₂ +
ρV₂²
Making p₂ the subject of the equation above;
p₂ = p₁ +
ρV₁² -
ρV₂²
But
so,
p₂ = p₁ +
ρV₁² -
ρ
p₂ = 3.0 x 10⁴ + (
× 1000 × 12²) - (
× 1000 × 12²/4² )
P₂ = 3.0 x 10⁴ + 7.2 × 10⁴ - 4.05 x 10³
P₂ = 9.79 × 10⁴Pa
P₂ = 9.8 × 10⁴Pa
Answer:
3.33 Joules Per Second
Explanation:
Before finding the Power, we need to calculate the Work Done. The Work Done can be calculated using the formula:
WD = F × d
where F is the Magnitude of Force in <em>N</em>
<em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em>d is the Parallel Distance moved by the object in <em>m</em><em>.</em>
Hence, by Applying this formula, we get:
WD = (5)(20)
= 100 J
From here calculating Power is simple as it is the Rate of Work Done. Hence,
Power = 100/30
= <u>3</u><u>.</u><u>3</u><u>3</u><u> </u><u>J</u><u>/</u><u>s</u>
Therefore, the power put out is <u>3</u><u>.</u><u>3</u><u>3</u><u> </u><u>J</u><u>o</u><u>u</u><u>l</u><u>e</u><u>s</u><u> </u><u>p</u><u>e</u><u>r</u><u> </u><u>S</u><u>e</u><u>c</u><u>o</u><u>n</u><u>d</u><u>.</u>
I think the answer is constant