A man ran the 200m race within 19.19 seconds. Calculate the speed of the man during the race

Which physical phenomena is responsible for the earth’s sky appearing blue? scattering reflection dispersion refraction

klio [65]

Answer: Scattering reflection

Sunlight reaches earth's atmosphere and is scattered in all directions by all the gasses and particles in the air. Blue light is seen more than others because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.

Explanation:

7 0

3 years ago

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A rock is dropped (from rest) off a bridge over the Merrimack River. The falling rock

rewona [7]

Answer:

31.25 meters or ~31 meters approximately

Explanation:

Let's see which of the 5 variables we are given since this is a constant acceleration problem.

$v_i \ \ \ \ \ \ t \\ v_f \ \ \ \ \ \triangle x \\ a$

We want to find the height of the bridge, aka the vertical displacement of the rock. Let's set the upwards direction to be positive and the downwards direction to be negative.

We are told that the acceleration is 10 m/s² downward, so we have a = -10 m/s².

We are also told that the time it takes the rock to hit the water is 2.5 seconds. Time is the same regardless of the x- or y- direction, so we can say that t = 2.5 seconds.

Now, we aren't told this directly, but we can figure out that the velocity in the y-direction is 0 m/s, since the rock is dropped from rest off the bridge. Therefore, $v_i=0 \frac{m}{s}$ .

We want to find the vertical displacement, the height of the bridge, so we can say that $\triangle x= \ ?$

We have 4 out of 5 variables:

$v_i,\ a, \ t, \ \triangle x$

Look through the constant acceleration equations to see which equation has all 4 of these variables. You should come up with this one (no final velocity):

$x_f=x_i+v_it+\frac{1}{2}at^2$

Subtract $x_i$ from both sides of the equation to get:

$\triangle x=v_it+\frac{1}{2}at^2$

Substitute in our known variables and solve for delta x.

$\triangle x=(0\frac{m}{s})(2.5s) + \frac{1}{2} (-10\frac{m}{s^2})(2.5s)^2$

0 m/s multiplied by 2.5 s is 0, so we have:

$\triangle x =\frac{1}{2} (-10)(2.5)^2$

Evaluate the exponent first and multiply the terms together.

$\triangle x =(-5)(6.25)$
$\triangle x =-31.25$

The vertical displacement is -31.25 meters from the rock's starting position, so we can say that the height of the bridge is 31.25 meters, which is approximately 31 meters tall.

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3 years ago

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A(n) 77.5 kg astronaut becomes separated from the shuttle, while on a space walk. She finds herself 37.3 m away from the shuttle

NeX [460]

Answer:

Explanation:

The speed of the astronaut can be found with the help of law of conservation of momentum .

mv = MV , M is mass of astronaut , m is mass of object thrown , v is velocity of object thrown and V is velocity of astronaut.

Putting the values

77.5 x V = .94 x 12

V = .14554 m /s

This will be the uniform velocity of astronaut.

Distance to be covered = 37.3 m

time taken = distance / velocity

= 37.3 / .14554

= 256.28 s

= 4.27 minutes.

4 0

3 years ago

Problem 10.32

Mashcka [7]

Answer : $\alpha = -240\ rad/s^{2}$ south

Explanation :

Given that,

Force = 200 N

Length = 2.00 m

Mass = 5.00 kg

We know that , the formula of the angular acceleration

$\alpha = \dfrac{\tau}{I}\ rad/s^{2}$

We know the moment of inertia of rod

$I = \dfrac{ML^{2}}{12}$

Now, the torque is

$\tau = F\times r$

The angular acceleration

$\alpha = \dfrac{F\times r\times12}{ML^{2}}$

$\alpha = \dfrac{((200\ N\times-1\ m) + (-200\ N)\times(1\ m))\times12}{5\ kg\times2\ m\times2\ m}$

$\alpha = \dfrac{-400Nm\times12}{5kg\times4m^{2}}$

$\alpha = -240\ rad/s^{2}$

Negative sign represent of south direction.

Hence, this is the required solution.

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3 years ago

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Estefan has determined his BMI at 31. Explain how he can apply the FITT training principles to improve his body composition.

-BARSIC- [3]

Frequency:

Cardio : Five or more
HIIT: 5 or 4

Strength: 2-3 days on non-consecutive days a week

Intensity:
How hard you work during the session

For cardio : workout at your target heart rate.
For HIIT: varying intensity from high to low or rest ( no slow pace)
For strength: you should lift enough weight to complete the needed number of reps and sets.

Time:

For cardio 30- 60 min
For HIIT 45 min (short periods of bursts followed by rest)

For strength depends on the amount of weight.

Type:

Either cardio, HIIT or strength training (resistance training)

NOTE: This info is given by an unqualified brofessor, who uses his hard gained bro-science in the expense of scientific facts to solve others broblems.

7 0

4 years ago