Which mechanism(s) of heat transfer will work in a vacuum?

By which method does heat travel from the sun to Earth? A. Conduction B. Convection C. Evaporation D. Radiation

qaws [65]

Answer:

radiation

Explanation:

7 0

3 years ago

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how difficult is it to start a heavy lorry moving and to stop it moving? (choose one answer from the image provided)

ale4655 [162]

Answer:

option B

Explanation:

3 0

3 years ago

Carry out the following arithmetic operations. (Enter your answers to the correct number of significant figures.) My Notes Ask Y

morpeh [17]

Answer :

(a) The answer will be $\Rightarrow 562$

(b) The answer will be $\Rightarrow 2.0$

(c) The answer will be $\Rightarrow 49.32$

Explanation :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

The rule apply for the multiplication and division is :

The least number of significant figures in any number of the problem determines the number of significant figures in the answer.

The rule apply for the addition and subtraction is :

The least precise number present after the decimal point determines the number of significant figures in the answer.

(a) The sum of the measured values 521, 31.4, 0.85, and 9.0

$521+31.4+0.85+9.0$

$\Rightarrow 562.25$

In the given expression, 521 has 3 significant figures, 31.4 has 3 significant figures, 0.85 has 2 significant figures and 9.0 has 2 significant figures. From this we conclude that least precise number present after the decimal point is 0.

Thus, the answer will be $\Rightarrow 562$

(b) The product 0.0052 × 386.2

$(0.0052)\times (386.2)$

$\Rightarrow 2.00824$

In the given expression, 0.0052 has 2 significant figures and 386.2 has 4 significant figures. From this we conclude that 2 is the least significant figures in this problem. So, the answer should be in 2 significant figures.

Thus, the answer will be $\Rightarrow 2.0$

(c) The product $15.70\times \pi$

The value of $\pi$ = 3.141414 = $3.\bar {14}$

$\pi$ is an irrational number.

$(15.70)\times (3.1414)$

$\Rightarrow 49.31998$

In the given expression, 15.70 has 4 significant figures and $3.\bar {14}$ has infinite significant figures. From this we conclude that 4 is the least significant figures in this problem. So, the answer should be in 4 significant figures.

Thus, the answer will be $\Rightarrow 49.32$

3 0

4 years ago

Which best describes why Keplers observation of planetary motion is a law instead of a theory

svet-max [94.6K]

Kepler's first law - sometimes referred to as the law of ellipses - explains that planets are orbiting the sun in a path described as an ellipse. An ellipse can easily be constructed using a pencil, two tacks, a string, a sheet of paper and a piece of cardboard. Tack the sheet of paper to the cardboard using the two tacks. Then tie the string into a loop and wrap the loop around the two tacks. Take your pencil and pull the string until the pencil and two tacks make a triangle (see diagram at the right). Then begin to trace out a path with the pencil, keeping the string wrapped tightly around the tacks. The resulting shape will be an ellipse. An ellipse is a special curve in which the sum of the distances from every point on the curve to two other points is a constant. The two other points (represented here by the tack locations) are known as the foci of the ellipse. The closer together that these points are, the more closely that the ellipse resembles the shape of a circle. In fact, a circle is the special case of an ellipse in which the two foci are at the same location. Kepler's first law is rather simple - all planets orbit the sun in a path that resembles an ellipse, with the sun being located at one of the foci of that ellipse.

5 0

3 years ago

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What are two major motions of earth as it travels through space?

Reptile [31]

1. revolution
2. rotation

3 0

4 years ago

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