How to Calculate the pressure on its base.

A 78.5-kg man floats in freshwater with 3.2% of his volume above water when his lungs are empty, and 4.85% of his volume above w

Dima020 [189]

Answer:

A) V_air = 1.295 L

B) Volume is not reasonable

Explanation:

A) Let;

m be total mass of the man

m_p be the mass of the man that pulled out of the water because of the buoyant force that pulled out of the lung

m_3 be the mass above the water with the empty lung

m_5 be the mass above the water with full lung

F_b be the buoyant force due to the air in the lung

V_a be the volume of air inside man's lungs

w_p be the weight that the buoyant force opposes as a result of the air.

Now, we are given;

m = 78.5 kg

m_3 = 3.2% × 78.5 = 2.512 kg

m_5 = 4.85% × 78.5 = 3.80725 kg

Now, m_p = m_5 - m_3

m_p = 3.80725 - 2.512

m_p = 1.29525 kg

From archimedes principle, we have the formula for buoyant force as;

F_b = (m_displaced water)g = (ρ_water × V_air × g)

Where ρ_water is density of water = 1000 kg/m³

Thus;

F_b = w_p = 1.29525 × 9.81

F_b = 12.7064 N

As earlier said,

F_b = (ρ_water × V_air × g)

Thus;

V_air = F_b/(ρ_water × × g)

V_air = 12.7064/(1000 × 9.81)

V_air = 1.295 × 10^(-3) m³

We want to convert to litres;

1 m³ = 1000 L

Thus;

V_air = 1.295 × 10^(-3) × 1000

V_air = 1.295 L

B) From research, the average lung capacity of an adult human being is 6 litres of air.

Thus, the calculated lung volume is not reasonable

4 0

3 years ago

10. A 90 kg box is sliding across a surface at a constant velocity while experiencing a rightward applied

ANEK [815]

If the box is moving at constant velocity, net force must be zero, so:

F + fr = 0

fr = -F

4 0

3 years ago

Read 2 more answers

SP: Calculate the moment

ipn [44]

Answer:

Moment of the force is 20 N-m.

Explanation:

Given:

Force exerted by the person is, $F=80\ N$

Distance of application of force from the point about which moment is needed is, $d=25\ cm=\frac{25}{100}\ m=0.25\ m$

Now, we know that, moment of a force 'F' about a point at a perpendicular distance of 'd' from the same point is given as the product of the force and the perpendicular distance.

Therefore, the moment of the force about the end of the claw hammer is given as:

$M=F\times d\\\\M=(80\ N)(0.25\ m)\\\\M=20\textrm{ N-m}$

Hence, the moment of the force exerted by the person about the end of the claw hammer is 20 N-m.

6 0

3 years ago

I NEED AN ANSWER!

Lera25 [3.4K]

Answer:

Before sled starts to move it has a potential energy due to the elevation...and then that potential energy converted to kinetic energy due to presence of a velocity...the sled will continue to move if their is no resesive force...but however friction force is presence that cause the sled to stop....

5 0

3 years ago

What are the difference between conductor and insulator?

Anvisha [2.4K]

Answer:

A conductor allows energy e.g. electric charge or heat to pass through it easily. While an insulator does not let electric current or heat to travel through it.
Insulators have strong molecular bonds. While molecular bonds are very weak in conductors.
Insulators have very low conductivity. While in conductors, it is very high.
Insulators have a very high resistance and therefore the electrons are held together very firmly. The conductors, on the other hand, have a very low resistance.
Insulators do not have any electric field, neither inside nor on the surface. While in conductors, it is found on the surface and continues to be zero in the inner part of the conductor.

5 0

3 years ago