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3 years ago

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?

Physics

1 answer:

svetoff [14.1K]3 years ago

6 0

Average speed = (total distance covered) / (time to cover the distance)

-- Traveling at 40 mph for 1 hour, the distance covered is 40 miles.

-- Traveling at 60 mph for 1 hour, the distance covered is 60 miles.

-- Total distance covered = (40 miles) + (60 miles) = 100 miles

-- Total time = (1 hour) + (1 hour) = 2 hours

-- Average speed = (100 miles) / (2 hours)

<em>Average speed = 50 miles per hour</em>

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When you look at the backside of a shiny teaspoon held at arm's length, do you see yourself upright or upside down? (b) When you

igor_vitrenko [27]

Answer:

a) The back spoon gives a right image (upright)

b) the front gives an inverted image

Explanation:

The spoon is a curved metallic object, when we see ourselves from the back we have a convex mirror, in this type of mirror when the law of reflection is applied the rays diverge therefore the eye-brain system forms the image with the prolongation of the rays, therefore the image is straight and smaller than the object.

When we look through the deep side of the spoon, we have a concave mirror and as the object (we) is further away than the distance, the rays converge to a point, so the image is real, inverted smaller than the object.

In summary.

a) The back spoon gives a right image (upright)

b) the front gives an inverted image

3 0

2 years ago

peach pie in a 9.00 in diameter plate is placed upon a rotating tray. Then, the tray is rotated such that the rim of the pie pla

zavuch27 [327]

Explanation:

It is given that,

Diameter of the peach pie, d = 9 inches

Radius of the pie, r = 4.5 inches

The tray is rotated such that the rim of the pie plate moves through a distance of 183 inches, d = 183 inches

Let $\theta$ is the angular distance that the pie plate has moved through.

It is given by :

$\theta=\dfrac{d}{r}$

$\theta=\dfrac{183}{4.5}$

$\theta=40.66\ radian$

Since, 1 radian = 57.29 degrees

$\theta=2329.64\ degrees$

Since, 1 radian = 0.159155 revolution

$\theta=6.47124\ revolution$

Hence, this is the required solution.

5 0

3 years ago

A heat engine has a maximum possible efficiency of 0.780. If it operates between a deep lake with a constant temperature of-24.8

Volgvan

Answer : The temperature of the hot reservoir (in Kelvins) is 1128.18 K

Explanation :

Efficiency of carnot heat engine : It is the ratio of work done by the system to the system to the amount of heat transferred to the system at the higher temperature.

Formula used for efficiency of the heat engine.

$\eta =1-\frac{T_c}{T_h}$

where,

$\eta$ = efficiency = 0.780

$T_h$ = Temperature of hot reservoir = ?

$T_c$ = Temperature of cold reservoir = $-24.8^oC=273+(-24.8)=248.2K$

Now put all the given values in the above expression, we get:

$\eta =1-\frac{T_c}{T_h}$

$0.780=1-\frac{248.2K}{T_h}$

$T_h=1128.18K$

Therefore, the temperature of the hot reservoir (in Kelvins) is 1128.18 K

8 0

3 years ago

What are other countries public reaction to climate change?

tangare [24]

Other countries have reacted the same way as the United States has.

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3 years ago

What is trapezord mean

igor_vitrenko [27]

A quadrilateral with only one pair of parallel sides.
<span>a small carpal bone in the base of the hand, articulating with the metacarpal of the index finger.
</span>

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3 years ago