Ask question

Ask question

All categories

erastovalidia [21]

2 years ago

8

What are the two types of physical fitness?

1 answer:

Marina86 [1]2 years ago

4 0

<em><u>your </u></em><em><u>question</u></em><em><u>:</u></em><em><u> </u></em>

<em>What are the two types of physical fitness?</em>

<em><u>answer:</u></em>

<em>The</em><em> </em><em>two </em><em>types </em><em>of </em><em>phys</em><em>ical </em><em>fitn</em><em>e</em><em>s</em><em>s</em><em> </em><em>are </em><em>Health-related</em><em> physical fitness and Performance-related physical fitness.</em>

You might be interested in

HELP ASAP PLEASE!!!!!!!

pshichka [43]

Answer:a

Explanation: the plates shifts cracking making earthquakes

8 0

2 years ago

What does itmean to have an acceleration of 8 m/s2

Masteriza [31]

Answer:

The answer is option A.

You speed up 8 m/s every second

Hope this helps you

8 0

2 years ago

Read 2 more answers

Determine the power that needs to besupplied by the fanifthe desired velocity is 0.05 m3/s and the cross-sectional area is 20 cm

Mariulka [41]

Answer:

A fan with an energy efficiency of 30 % would need 62.5 watts to bring a desired volume flow of 0.05 cubic meters per second through a cross-sectional area of 20 square centimeters.

Explanation:

Complete statement is: <em>Determine the power that needs to besupplied by the fan if the desired velocity is 0.05 cubic meters per second and the cross-sectional area is 20 square centimeters.</em>

From Thermodynamics and Fluid Mechanics we know that fans are devices that work at steady state which accelerate gases (i.e. air) with no changes in pressure. In this case, mechanical rotation energy is transformed into kinetic energy. If we include losses due to mechanical friction, the Principle of Energy Conservation presents the following equation:

$\eta\cdot \dot W = \dot K$

$\dot W = \frac{\dot K}{\eta}$ (Eq. 1)

Where:

$\eta$ - Efficiency of fan, dimensionless.

$\dot W$ - Electric power supplied fan, measured in watts.

$\dot K$ - Rate of change of kinetic energy of air in time, measured in watts.

From definition of kinetic energy, the equation above is now expanded:

$\dot W = \frac{\rho_{a}\cdot \dot V}{2\cdot \eta}\cdot \left(\frac{\dot V}{A_{s}} \right)^{2}$ (Eq. 2)

Where:

$\rho_{a}$ - Density of air, measured in kilograms per cubic meter.

$\dot V$ - Volume flow, measured in cubic meters per second.

$A_{s}$ - Cross-sectional area of fan, measured in square meters.

If we know that $\rho_{a} = 1.20\,\frac{kg}{m^{3}}$ , $\dot V = 0.05\,\frac{m^{3}}{s}$ , $\eta = 0.3$ and $A_{s} = 20\times 10^{-4}\,m^{2}$ , the power needed to be supplied by the fan is:

$\dot K = \left[\frac{\left(1.20\,\frac{kg}{m^{3}} \right)\cdot \left(0.05\,\frac{m^{3}}{s} \right)}{2\cdot (0.3)} \right]\cdot \left(\frac{0.05\,\frac{m^{3}}{s} }{20\times 10^{-4}\,m^{2}} \right)^{2}$

$\dot K = 62.5\,W$

A fan with an energy efficiency of 30 % would need 62.5 watts to bring a desired volume flow of 0.05 cubic meters per second through a cross-sectional area of 20 square centimeters.

5 0

3 years ago

Your answer should be precise to 0.1 m/s. Use a gravitational acceleration of 10 m/s/s. At it lowest point, a pendulum is moving

saw5 [17]

Explanation:

It is given that,

Speed, v₁ = 7.7 m/s

We need to find the velocity after it has risen 1 meter above the lowest point. Let it is given by v₂. Using the conservation of energy as :

$\dfrac{1}{2}mv_1^2=\dfrac{1}{2}mv_2^2+mgh$

$v_2^2=v_1^2-2gh$

$v_2^2=(7.7)^2-2\times 10\times 1$

$v_2=6.26\ m/s$

So, the velocity after it has risen 1 meter above the lowest point is 6.26 m/s. Hence, this is the required solution.

4 0

3 years ago

Read 2 more answers

A car with a momentum (impulse) of 20,000 kg m/s collides with a wall and comes to a rest in 0.1 seconds. How much

Pani-rosa [81]

Answer:

» Force is 200,000 Newtons

Explanation:

${ \tt{force = \frac{impulse}{time} }} \\ \\ { \tt{force = \frac{20000}{0.1} }} \\ \\ { \tt{force = 200000 \: newtons}}$

8 0

2 years ago

Read 2 more answers