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3 years ago

For convection to occur,

1 answer:

4 0

C. Convection is the transfer of energy by the motion of a fluid. Fluids are by definition substances in which particles are able to flow. Hence the answer is c

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to start an avalanche on a mountain slope, an artillery shell is fired with an initial velocity of 290 m/s at 53.0° above the ho

kap26 [50]

So this is easy to calculate when you split the velocity into x and y components. The x component is going to equal cos(53) * 290 and the y component is going to equal sin(53)*290.

The x location therefore is 290*cos(53)*35 = 6108.4m

The y location needs to factor in the downwards acceleration of gravity too, which is 9.81m/s^2. We need the equation dist. = V initial*time + 0.5*acceleration*time^2.

This gives us d=290*sin(53)*35 + (0.5*-9.81*35^2)=2097.5m

So your (x,y) coordinates equals (6108.4, 2097.5)

5 0

2 years ago

When iron rusts, iron atoms are destroyed true or false?

vfiekz [6]

False. this is just a physical change, not a chemical change.

3 0

2 years ago

The component of the external magnetic field along the central axis of a 78-turn circular coil of radius 34.0 cm decreases from

grigory [225]

Answer:

Induced current, I = 18.88 A

Explanation:

It is given that,

Number of turns, N = 78

Radius of the circular coil, r = 34 cm = 0.34 m

Magnetic field changes from 2.4 T to 0.4 T in 2 s.

Resistance of the coil, R = 1.5 ohms

We need to find the magnitude of the induced current in the coil. The induced emf is given by :

$\epsilon=-N\dfrac{d\phi}{dt}$

Where

$\dfrac{d\phi}{dt}$ is the rate of change of magnetic flux,

And $\phi=BA$

$\epsilon=-NA\dfrac{dB}{dt}$

$\epsilon=-78\times \pi (0.34)^2\dfrac{(0.4-2.4)}{2}$

$\epsilon=28.32\ V$

Using Ohm's law, $\epsilon=I\times R$

Induced current, $I=\dfrac{\epsilon}{R}$

$I=\dfrac{28.32}{1.5}$

I = 18.88 A

So, the magnitude of the induced current in the coil is 18.88 A. Hence, this is the required solution.

5 0

2 years ago

A 2.51 kg ball is attached to a ceiling by a 1.19 m long string. The height of the room is 3.45 m. The acceleration of gravity i

ANTONII [103]

Answer:

55,42 J

Explanation:

Since the height of the room is 3.45 m (distance between the floor and the ceiling) the difference between this value and the length of the rope 1.19 m; it will be equal to (3.45-1.19) =2.26 m. If we take as a reference point (Ep=0) the floor of the room, then the potential energy will be equal to Ep = M * g * h, replacing values in this equation (2.5 kg * 9.81 m/s2 * 2.26 m) will be 55,42 (N * m) or Jules.

6 0

2 years ago

A drone is flying horizontally when it runs out of battery and begins to free fall from 20m. No drag. If it lands 60m away (in t

rewona [7]

Answer:

Explanation:

Remark

At the time it takes to drop 20 m is the same time it takes to travel 60 m horizontally.

Givens

h = 20 m

hd = 60 m

g = 9.81

vi = 0

Formula

d = vi*t + 1/2 a * t^2 We are solving for t

Solution

When the battery fails, the vertical initial velocity is 0. So we have to find the time it would take to drop 20 meters

d = 0*t + 1/2 * 9.81 a* t^2

20 = 4.91 * t^2 Divide by 4.91

20/4.91 = 4.91 t^2 / 4.91

4.073 = t^2 Take the square root of both sides.

t = 2.02 seconds

Horizontal

d = 60 m

t = 2.02 seconds

v = ?

Note: there is no horizontal deceleration or acceleration

v = d/t

v = 60/2.02

Answer: v = 29.73 m/s

3 0

1 year ago