All categories

3 years ago

Cardiovascular fitness can be measured by what?

1 answer:

5 0

VO2 max is considered to be the most valid measure of cardio respiratory fitness. It measures the capacity of the heart, lungs, and blood to transport oxygen to the working muscles, and measures the utilization of oxygen by the muscles during exercise.

You might be interested in

A satellite in outer space is moving at a constant velocity of 21.4 m/s in the y direction when one of its onboard thruster turn

kumpel [21]

Answer:

a) The magnitude of the satellite's velocity when the thruster turns off is approximately 24.177 meters per second.

b) The direction of the satellite's velocity when the thruster turns off is approximately 62.266º.

Explanation:

Statement is incomplete. The complete description is now described below:

A satellite in outer space is moving at a constant velocity of 21.4 m/s in the y direction when one of its onboard thruster turns on, causing an acceleration of 0.250 m/s2 in the x direction. The acceleration lasts for 45.0 s, at which point the thruster turns off.

(a) What is the magnitude of the satellite's velocity when the thruster turns off

(b) What is the direction of the satellite's velocity when the thruster turns off? Give your answer as an angle measured counterclockwise from the +x-axis. ° counterclockwise from the +x-axis

Let be x and y-directions orthogonal to each other and the satellite is accelerated uniformly from rest in the +x direction and moves at constant velocity in the +y direction. The velocity vector of the satellite ( $\vec{v}_{S}$ ), measured in meters per second, is:

$\vec{v}_{S} = (v_{o,x}+a_{x}\cdot t)\,\hat{i}+v_{y}\,\hat{j}$

Where:

$v_{o,x}$ - Initial velocity in +x direction, measured in meters per second.

$a_{x}$ - Acceleration in +x direction, measured in meter per square second.

$t$ - Time, measured in seconds.

$v_{y}$ - Velocity in +y direction, measured in meters per second.

If we know that $v_{o,x} = 0\,\frac{m}{s}$ , $a_{x} = 0.250\,\frac{m}{s^{2}}$ , $t = 45\,s$ and $v_{y} = 21.4\,\frac{m}{s}$ , the final velocity of the satellite is:

$\vec{v}_{S} = \left[0\,\frac{m}{s}+\left(0.250\,\frac{m}{s^{2}} \right)\cdot (45\,s) \right]\,\hat{i}+\left(21.4\,\frac{m}{s} \right)\,\hat{j}$

$\vec{v_{S}} = 11.25\,\hat{i}+21.4\,\hat{j}\,\,\left[\frac{m}{s} \right]$

a) The magnitud of the satellite's velocity can be found by the resource of the Pythagorean Theorem:

$\|\vec {v}_{S}\| = \sqrt{\left(11.25\,\frac{m}{s} \right)^{2}+\left(21.4\,\frac{m}{s} \right)^{2}}$

$\|\vec{v}_{S}\| \approx 24.177\,\frac{m}{s}$

The magnitude of the satellite's velocity when the thruster turns off is approximately 24.177 meters per second.

b) The direction of the satellite's velocity when the thruster turns off is determined with the help of trigonometric functions:

$\tan \alpha = \frac{v_{y}}{v_{x}} = \frac{21.4\,\frac{m}{s} }{11.25\,\frac{m}{s} }$

$\tan \alpha = 1.902$

$\alpha = \tan^{-1}1.902$

$\alpha \approx 62.266^{\circ}$

The direction of the satellite's velocity when the thruster turns off is approximately 62.266º.

4 0

2 years ago

You want to put a new CD in your car stereo.While driving at 45 mi/h,you look away for 2.0s.What distance (in miles) do you driv

KengaRu [80]

Answer:

You drive 0.025 miles blind (or 132 ft)

Explanation:

(distance) = (speed) x (time)

(distance blind) = (speed) x (time looking for CD)

(distance blind) = (45 mi/hr) x (2 s) x (1/3600 hr/s) = 0.025 miles = 132 ft

3 0

3 years ago

As water rises through the troposphere and cools, it changes from a(n) ————- to a(n) ———— through the process of condensation; w

Hoochie [10]

Answer:

GAS, LIQUID, CLOUDS

Explanation:

Water can be in three states: solid, liquid and gas, passing from one to another depending on the pressure and temperature.

In this complementation exercise.

When the water cools down the GAS goes to the LIQUID state, these small drops unite and form the CLOUDS

4 0

2 years ago

What is the word for a group of stars that’s not a constellation?.

Sever21 [200]

Asterism, a pattern of stars that is not a constellation. An asterism can be part of a constellation, such as the Big Dipper, which is in the constellation Ursa Major, and can even span across constellations, such as the Summer Triangle, which is formed by the three bright stars Deneb, Altair, and Vega.

7 0

2 years ago

5. A weightlifter lifts a barbell of mass 50 kg to a height of 2m in 3s. (Take g = 9.8 m/s².) a) What is the weight of the barbe

inysia [295]

Answer:

490N

Explanation:

W=m×g

W=50×9.8=490N

4 0

1 year ago