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2 years ago

13

If the boat's engine has a heat of 40,000 J, with 30,000 J exhausted into the surroundings (the heat sink), what is its efficien

cy? Show your work.

1 answer:

Yuliya22 [10]2 years ago

7 0

The answer to your quistion will be 75%

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__________ enable humans to see and detect the color of different objects.

Llana [10]

The correct answer is C.

6 0

3 years ago

Read 2 more answers

What is the period (in hours) of a satellite circling Mars 100 km above the planet's surface? The mass of Mars is 6.42 × 1023 kg

scZoUnD [109]

To solve this problem it is necessary to apply the concepts related to the Centrifugal Force and the Gravitational Force. Since there is balance on the body these two Forces will be equal, mathematically they can be expressed as

$F_c = F_g$

$\frac{mv^2}{r} = \frac{GmM}{r^2}$

Where,

m = Mass

G =Gravitational Universal Constant

M = Mass of the Planet

r = Distance/Radius

Re-arrange to find the velocity we have,

$v^2 = \frac{GM}{r}$

At the same time we know that the period is equivalent in terms of the linear velocity to,

$T = \frac{2\pi}{\frac{v}{r}}$

$v = \frac{2\pi r}{T}$

If our values are that the radius of mars is 3400 km and the distance above the planet is 100km more, i.e, 3500km we have,

$v^2 = \frac{GM}{r}$

$( \frac{2\pi r}{T})^2 = \frac{GM}{r}$

$T = \sqrt{\frac{4\pi^2 r^3}{GM}}$

Replacing we have,

$T = \sqrt{\frac{4\pi^2 (3500*10^3)^3}{(6.67430*10^{-11})(6.42*10^23)}}$

$T = 6285.09s (\frac{1min}{60s})(\frac{1hour}{60min})$

$T= 1.74hour$

Therefore the correct answer is C.

7 0

3 years ago

In the doorknob shown above, when the handle is rotated a distance of 189 millimeters, the spindle is rotated a distance of 27 m

Alisiya [41]

If my math is right its A) 7

because 189 divided by 27 is 7

7 0

3 years ago

Read 2 more answers

1- A train travels 92 kilometers in 3 hours, and then 55 kilometers in 3 hours. What is its average speed?

Hunter-Best [27]

<h3>Answer:</h3>

24.5 km/h
4 17/27 m/s
11/3 m/s²

<h3>Explanation:</h3>

1. The average speed is the ratio of total distance to total time:

... speed = distance/time = (92 km +55 km)/(3 h +3h) = (147 km)/(6 h)

... = 24.5 km/h

2. speed = distance/time = (125 m)/(27 s) = 4 17/27 m/s

3. a = ∆v/∆t = (15 m/s -4 m/s)/(3 s) = 11/3 m/s²

8 0

3 years ago

HELP! block is released from rest and slides down a frictionless ramp inclined at 30' from the horizontal. When the block reache

Bumek [7]

Answer:

A

Explanation:

the horizontal and vertical force acting on it consist a net force on the inclined direction (30degrees below the horizontal) you can tell by the length of the horizontal component (try to see the 30degree incline as horizontal, because that's the direction of the displacement). net work done on the system results in an increase in energy. i hope this can help :D, i'm also taking the ap physics 1 exam tommorow.

5 0

2 years ago