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3 years ago

How long does it take someone to run 8 miles if they are running at a speed of 7 km/hr?

Physics

1 answer:

ZanzabumX [31]3 years ago

7 0

Answer:

1.84 hours or 110.4 minutes

Explanation:

8 miles 1.61 km 1 hr

------------ x ----------------- x -------------- = 1.84 hours or 110.4 minutes

1 mile 7 km

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You perform an experiment to measure the speed of a car over time. The results are shown in the graph below. What is the best in

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3 years ago

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The process by which hot and cold air are transferred in the atmosphere is

Nuetrik [128]

That process is convection.

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2 years ago

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A wheel rotating about a fixed axis has a constant angular acceleration of 4.0 rad/s2. In a 4.0-s interval the wheel turns throu

Nady [450]

Answer:

The time interval is $t = 3 \ s$

Explanation:

From the question we are told that

The angular acceleration is $\alpha = 4.0 \ rad/s^2$

The time taken is $t = 4.0 \ s$

The angular displacement is $\theta = 80 \ radians$

The angular displacement can be represented by the second equation of motion as shown below

$\theta = w_i t + \frac{1}{2} \alpha t^2$

where $w_i$ is the initial velocity at the start of the 4 second interval

So substituting values

$80 = w_i * 4 + 0.5 * 4.0 * (4^2)$

=> $w_i = 12 \ rad/s$

Now considering this motion starting from the start point (that is rest ) we have

$w__{4.0 }} = w__{0}} + \alpha * t$

Where $w__{0}}$ is the angular velocity at rest which is zero and $w__{4}}$ is the angular velocity after 4.0 second which is calculated as 12 rad/s s

$12 = 0 + 4 t$

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4 0

2 years ago

Piano tuners tune pianos by listening to the beats between the harmonics of two different strings. When properly tuned, the note

mote1985 [20]

Answer:

Frequency = 658 Hz

Explanation:

The third harmonics of A is,

$f_{A}=(3)(440Hz)=1320Hz$

The second harmonics of E is,

$f_{E}=(2)(659Hz)=1318Hz$

The difference in the two frequencies is,

delta_f = 1320 Hz - 1318 Hz = 2 Hz

The beat frequency between the third harmonic of A and the second harmonic of E is,

delta_f = $3f_{A}-2f_{E}$

$f_{E}=\frac{3f_{A}-delta_f}{2}$

We have calculate the frequency of the E string when she hears four beats per second, then

delat_f = 4 Hz

$f_{E}=\frac{3(440Hz)-4Hz}{2}$

$f_{E}=658Hz$

Hope this helps!

5 0

3 years ago

A 63.3 kg wood board is resting on very smooth ice in the middle of a frozen lake. A 35.7 kg boy stands at one end of the board.

Vlada [557]

The velocity of the board relative to the ice is zero, since both are at rest.

<h3>What is relative velocity?</h3>

Relative velocity is the velocity of an object in relation to another reference object or point.

When two objects are travelling or moving with the same velocity in the same direction, the relative velocity one relative to the other is zero.

Also, when two objects are at rest, the relative velocity one relative to the other is zero.

Therefore, the velocity of the board relative to the ice is zero, since both are at rest.

Learn more about relative velocity at: brainly.com/question/24337516

#SPJ1

8 0

2 years ago