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3 years ago

7. What is the force of air resistance on an

Physics

1 answer:

Murrr4er [49]3 years ago

7 0

Answer:

C) 464 N

Explanation:

The equation of the forces acting on the skydiver is:

$mg-R=ma$

where

(mg) is the weight of the skydiver, acting downward, with

m being the mass of the skydiver

g is the acceleration of gravity

R is the air resistance, acting upward

a is the acceleration of the skydiver

In this problem:

m = 80 kg

g = 9.8 m/s^2

a = 4.0 m/s^2

Solving the equation for R, we find the force of air resistance:

$r=mg-ma=m(g-a)=(80)(9.8-4.0)=464 N$

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A liquid is flowing through a horizontal pipe whose radius is m. The pipe bends straight upward through a height of 10.6 m and j

zaharov [31]

Answer:

Volume flow rate $= 1.81 * 10^{-2}$ meter cube per second

Explanation:

As we know that the

Pressure at the two ends would be the same along with volume of flow.

i.e

$P_1 = P_2$

and

$A_1 V_1 = A_2 V_2$

Re arranging the file, we get -

$V_1 = \frac{A_2 V_2}{A_1}$

The flow equation is

$\frac{1}{2}\rho * V_1^2 = \frac{1}{2}\rho * V_2^2 + \rho * g * h\\$

Substituting the value of $V_1$ in above equation, we get -

$V_2 = \sqrt{\frac{2gh}{(\frac{A_2}{A_1})^2-1} }$

Substituting the given values in above equation we get

$V_2 = \sqrt{\frac{2*9.8*10.6}{(\frac{\pi 0.04^2}{\pi 0.02^2} )^2 -1} }\\ V_2 = 3.61 m$

Volume flow rate

$Q_2 = A_2 V_2\\= \pi r_2^2V_2^2\\= 3.14 * 0.04^2 * 3.61 \\= 1.81 * 10^{-2}$

7 0

3 years ago

Why isn't direct current used in transformers

Furkat [3]

Answer:

No, it will not and this has a historical importance. The reason is that transformers work via induction of electrical forces by changes in magnetic fields, so the constat fields produced by dc currents won't work at all

Explanation:

4 0

3 years ago

Read 2 more answers

At what distance will a 45 W lightbulb have the same apparent brightness as a 130 W bulb viewed from a distance of 35 m ? (Assum

Sloan [31]

Answer:

20.6 m

Explanation:

P₁ = Power of first bulb = 45 W

P₂ = Power of second bulb = 130 W

r₁ = distance from the first bulb

r₂ = distance from the second bulb = 35 m

Using the equation

$\frac{P_{1}}{r_{1}^{2}} = \frac{P_{2}}{r_{2}^{2}}$

Inserting the values

$\frac{45}{r_{1}^{2}} = \frac{130}{35^{2}}$

r₁ = 20.6 m

5 0

4 years ago

A 0.12 kg bird is flying at a constant speed of 7.8 m/s. what is the birds conetic energy?

lana [24]

KE=1/2mv^2 - equation for kinetic energy
KE=(1/2)(0.12 kg)((7.8 m/s)^2 - plug it into the formula
KE=(0.06 kg)(60.84 m/s) - multiply 1/2 to the mass and square the speed
KE= 3.7 J - answer
Hope this helps

7 0

4 years ago

Read 2 more answers

Bartek w czasie 2minut przesunął ruchem jednostajnym kamień na odległość 0,5m.Oblicz moc mięśni Bartka jeśli siła oporów wynsiła

Ipatiy [6.2K]

Answer:

Bartek's muscle power = 2.667 W

Moc mięśni Bartka = 2.667 W

Explanation:

English Translation

Bartek within 2 minutes moved the stone

steadily at a distance of 0.5 m. Calculate Bartek's muscle power , if the resistance force was 640N.

The power, P, expended or generated by moving a body to move a velocity, v, against a resistive force, F is given as

P = Fv

P = ?

F = 640 N

v = velocity = (0.5) ÷ (2×60) = 0.00416667 m/s

P = 640 × 0.0041666667 = 2.667 W

In Polish/Po polsku

Moc P, zużyta lub wytworzona przez poruszanie ciałem w celu przemieszczenia prędkości v przeciwko sile oporowej, F jest podawana jako

P = Fv

P = ?

F = 640 N

v = velocity = (0.5) ÷ (2×60) = 0.00416667 m/s

P = 640 × 0.0041666667 = 2.667 W

Hope this Helps!!!

Mam nadzieję że to pomoże!!

4 0

3 years ago