Which type of solar heating uses mechanical means?

A truck loaded with sand accelerates along a highway. The driving force on the truck remains constant. What happens to the accel

pickupchik [31]

Answer:

Acceleration will increase.

Explanation:

The relation between force, mass and acceleration according to the Newton's second law of motion is given as:

F = ma

We are given that the driving force on the truck remains constant, so F is constant here. We can rewrite the above equation as:

$a=\frac{F}{m}$

Since, F is constant, the acceleration of the truck is inversely proportional to the mass.

There is a hole at the bottom of the truck through which the sand is being lost at a constant rate. Since, the sand is being lost, the overall mass of the truck is being reduced.

Since, the acceleration of the truck is inversely proportional to the mass, the reduced mass will result in an increased acceleration.

So, the acceleration of the truck will increase.

4 0

3 years ago

With 51 gallons of fuel in its tank, the airplane has a weight of 2390.7 pounds. What is the weight of the plane with 81 gallons

Shtirlitz [24]

Answer: 2561.7 pounds

Explanation:

If we assume the total weight of an airplane (in pounds units) as a linear function of the amount of fuel in its tank (in gallons) and we make a Weight vs amount of fuel graph, which resulting slope is 5.7, we can use the slope equation of the line:

$m=\frac{Y-Y_{1}}{X-X_{1}}$ (1)

Where:

$m=5.7$ is the slope of the line

$Y_{1}=2390.7pounds$ is the airplane weight with 51 gallons of fuel in its tank (assuming we chose the Y axis for the airplane weight in the graph)

$X_{1}=51gallons$ is the fuel in airplane's tank for a total weigth of 2390.7 pounds (assuming we chose the X axis for the a,ount of fuel in the tank in the graph)

This means we already have one point of the graph, which coordinate is:

$(X_{1},Y_{1})=(51,2390.7)$

Rewritting (1):

$Y=m(X-X_{1})+Y_{1}$ (2)

As Y is a function of X:

$Y=f_{(X)}=m(X-X_{1})+Y_{1}$ (3)

Substituting the known values:

$f_{(X)}=5.7(X-51)+2390.7$ (4)

$f_{(X)}=5.7X-290.7+2390.7$ (5)

$f_{(X)}=5.7X+2100$ (6)

Now, evaluating this function when X=81 (talking about the 81 gallons of fuel in the tank):

$f_{(81)}=5.7(81)+2100$ (7)

$f_{(81)}=2561.7$ (8) This means the weight of the plane when it has 81 gallons of fuel in its tank is 2561.7 pounds.

3 0

3 years ago

You place a light bulb 8 cm in front of a concave mirror. You then move a sheet of paper back and forth in front of the mirror.

Alika [10]

sorry - late reply...just stumbled across tis...hope u can still use it :)

By the mirror equation: 1/di + 1/do = 1/f

where di = distance to image = +12cm (+ for real image)

and do = distance to object = +8cm

Substitute and solve for f, the focal length

1/12 + 1/8 = 1/f

1/f = (8 + 12) / 12 * 8 = 20/96

so f = 96/20 = 4.8 cm

5 0

3 years ago

When an electric stove element is hot enough, it gives off a dull red glow. When it cools to the point that it no longer glows,

DochEvi [55]

Answer:

It will have a longer wavelength

Explanation:

When an electric stove is hot and gives dull red glow. a part of the energy dissipated is emitted as visible light and part as infrared radiation in the form of heat. When the stove cools down, and no longer glows all the energy is now in the form of infrared radiation.In the electromagnetic spectrum infrared rays have a higher wavelength than visible light. Hence for the reason the radiation will have a higher wavelength since visible light is cut off.

4 0

3 years ago

in a railyard a train is being put together from freight cars.An empty freight car coasting 10 m/s strikes a loaded car that is

svetoff [14.1K]

Answer:m1v1 + m2v2 = (m1f + m2f)vf. 3000kg(10.0m/s) + (15000kg)(0.0m/s) = (18000kg)(vf).

Explanation:

7 0

2 years ago