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2 years ago

How much time does it take a person to walk 12km north at the velocity at a velocity of 6.5 km/hrs?

2 answers:

8 0

I'm thinking this should actually go in the math section because you need to divide 12 by 6.5 to get the number of km/hour.

alukav5142 [94]2 years ago

6 0

"6.5 km/hr" is not a velocity. It's just a speed, so
we don't know what direction he's walking.

If he happens to be walking north, then it takes him

(12 km) / (6.5 km/hr) = 1.846... hours (rounded) .

If he's walking in any other direction, it takes him longer than that.

If the angle between north and the direction he's walking is
90 degrees or more, then he can never cover any northward
distance, no matter how long he walks.

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A long, thin solenoid has 450 turns per meter and a radius of 1.06 . The current in the solenoid is increasing at a uniform rate

kirill115 [55]

Answer:9.34 A/s

Explanation:

Given

radius of solenoid $R=1.06 m$

Emf induced $E=8.50\times 10^{-6} V/m$

no of turns per meter n=450

we know Induced EMF is given by

$\int Edl=-\frac{\mathrm{d} \phi}{\mathrm{d} t}=-\frac{\mathrm{d} B}{\mathrm{d} t}A$

Magnetic Field is given by

$B=\mu _0ni$

thus $\frac{\mathrm{d} B}{\mathrm{d} t}=-\mu _0n\frac{\mathrm{d} i}{\mathrm{d} t}$

Area of cross-section

$A=\pi R^2$ where

solving integration we get

$E.\cdot 2\pi r=\mu _0n\frac{\mathrm{d} i}{\mathrm{d} t}\pi R^2$

where r=distance from axis

R=radius of Solenoid

$\frac{\mathrm{d} i}{\mathrm{d} t}=\frac{Er}{\mu _0nR^2}$

$\frac{\mathrm{d} i}{\mathrm{d} t}=\frac{8.50\times 10^{-6}\times 3.49\times 10^{-2}}{4\pi \times 10^{-7}\times 450\times 1.06^2}$

$\frac{\mathrm{d} i}{\mathrm{d} t}=9.34 A/s$

4 0

3 years ago

A healthy astronaut's heart rate is 60 beats/min. Flight doctors on Earth can monitor an astronaut's vital signs remotely while

Anton [14]

GIVEN:
60 beats per minute
21 beats per minute
find x= how fast would an astronaut be flying away
1 x
----- * ------ = (60x = 21) -------> 60x = 21 ------------> x= 0.35
60 21 ------- -----
60 60

The answer is 0.35 seconds which refers to how fast would an astronaut be flying away from the earth if he has a heart rate of 21 beats/min.

5 0

2 years ago

Read 2 more answers

Warm air is more dense than cool air. Warm air is less dense than cool air Warm air and cool air have the same density

Wewaii [24]

Answer:

You are exactly right. The molecules in hot air are moving faster than the molecules in cold air. Because of this, the molecules in hot air tend to be further apart on average, giving hot air a lower density. That means, for the same volume of air, hot air has fewer molecules and so it weighs less

7 0

2 years ago

Two vectors have magnitudes of 10 and 15. The angle between them when they are drawn with their tails at the same point is 65. T

IrinaK [193]

Two vectors have magnitudes of 10 and 15. The angle between them when they are drawn with their tails at the same point is 65. The component of the longer vector along the line of the shorter is 6.33 .

A vector is a quantity or phenomenon that has two independent properties: magnitude and direction. The term also denotes the mathematical or geometrical representation of such a quantity. Examples of vectors in nature are velocity, momentum, force, electromagnetic fields, and weight.

The taller component will be 15 . There will be two components taller component , one in the direction of shorter component and other perpendicular to the shorter wavelength .

The component of longer wavelength in the direction of shorter will be

= 15 cos (theta ) = 15 cos (65) = 6.33

where theta is the angle between both the vectors

To learn more about vectors here

brainly.com/question/13322477

#SPJ4

3 0

1 year ago

a current of 5 ampere is passed for 2 hours in an electric iron having a resistance of 100 ohms calculate the heat produced

Alina [70]

Answer:

$\boxed{\sf Heat \ produced \ (H) = 5 \ kWh}$

Given:

Resistance (R) = 100 Ω

Current (I) = 5 A

Time (t) = 2 hours

To Find:

Heat developed (H) in the electric iron

Explanation:

Formula:

$\boxed{ \bold{ \sf H = I^2Rt}}$

Substituting values of I, R & t in the equation:

$\sf \implies H = {5}^{2} \times 100 \times 2 \\ \\ \sf \implies H = 25 \times 100 \times 2 \\ \\ \sf \implies H = 5000 \\ \\ \sf \implies H = 5 \: kWh$

$\therefore$

Heat developed (H) in the electric iron = 15 kWh

3 0

3 years ago