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2 years ago

5

Dave is walking from the back of a train to the front of the train at a rate of 6

1 answer:

monitta2 years ago

6 0

48 km/hr. Because the trains speed remains constant and is unaffected to Dave’s speed and Dave’s speed will remain relative to the trains speed. Taken that, when Dave is moving 0 km/hr he is moving at 42km/hr. So his speed must only add to that.

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Calculate potential energy

IrinaVladis [17]

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3 years ago

When is the best time to take a resting heart break

Olegator [25]

Answer:

I believe D

Explanation:

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I hope this is correct good luck!

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2 years ago

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An external force that is being applied in the direction of the displacement

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2 years ago

A room has a wall with an R value of 18 F sq.ft. hr/BTU. The room is 15 feet long and 11 feet wide with walls that are 9 ft high

seropon [69]

Answer:

The heat transferred through the wall that day is 13728 BTUs

Explanation:

Here, we have the area of the wall given as

Area of wall = 2 × Length × Height + 2 × Width × Height

Length = 15 feet

Width = 11 Feet and

Height = 9 feet

Therefore, the area = 2×15×9 + 2×11×9 = 468 ft²

Temperature difference is given by

Average outside temperature - Wall temperature = 40 - 18 = 22 °F

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3 years ago

Suppose the electric field in some region is found to be E = kr3 ˆr, in spherical coordinates (k is some constant). (a) Find the

Assoli18 [71]

Answer:

Part a)

$\rho = 3\epsilon_0 k r^2$

Part b)

$Q = 4\pi \epsilon_0kR^5$

Explanation:

Part a)

As we know that electric field intensity due to some given charge distribution is given as

$E = kr^3 \hat r$

now electric flux through a spherical surface of radius r is given as

$\phi = E. A$

$\phi = kr^3(4\pi r^2)$

now by Guass law we know that

$E.A = \frac{q}{\epsilon_0}$

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now volume charge density is given as

$\rho = \frac{q}{\frac{4}{3}\pi r^3}$

$\rho = 3\epsilon_0 k r^2$

Part b)

Total charge inside the radius R is given as

$Q = 4\pi \epsilon_0kR^5$

7 0

2 years ago