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3 years ago

The value of efficiency is never 100% or more in practice. why

1 answer:

3 0

Answer: Because of presence of friction in most cases as friction exists in ever machine/body, so whenever it works, friction causes heat and sound energy as well, hence, proving that a system cannot be 100% efficient due to friction.

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I The Circuit shows for Tamps Connected by Tovde supply

luda_lava [24]

.........,....,,,???........

4 0

2 years ago

Which of the following is the best definition of energy?

Montano1993 [528]

Energy is the capacity to do some type of work

8 0

3 years ago

A migrating robin flies due north with a speed of 12 m/s relative to the air. The air moves due east with a speed of 6.7 m/s rel

mafiozo [28]

Here it is given that speed of migrating Robin is 12 m/s relative to air

so we can say that

$\vec v_{ra} = 12 m/s$ North

so it will be

Let North direction is along Y axis and East direction is along X axis

$\vec v_{ra} = 12\hat j$

also it is given that speed of air is 6.7 m/s relative to ground

$\vec v_a = 6.7 \hat i$

now as we know by the concept of relative motion

$\vec v_{ab} = \vec v_a - \vec v_b$

$\vec v_{ra} = \vec v_r - \vec v_a$

now by rearranging the terms

$\vec v_r = \vec v_{ra} + \vec v_a$

$\vec v_r = 12 \hat j + 6.7 \hat i$

now we need to find the speed of Robin which means we need to find the magnitude of its velocity which we found above

So here we will say

$v_r = \sqrt{12^2 + 6.7^2}$

$v_r = 13.7 m/s$

so the net speed of Robin with respect to ground will be 13.7 m/s

7 0

3 years ago

True or false as heat and pressure decreases one type of metamorphic rock will transform into another type

dezoksy [38]

Answer: True

Explanation: Metamorphism is the changing of rocks by heat and pressure. During this process, rocks change either physically and/or chemically. They change so much that they become an entirely new rock. Figure 4.22: The platy layers in this large outcrop of metamorphic rock show the effects of pressure on rocks during metamorphism.

6 0

2 years ago

A. What is the frequency of blue light that has a wavelength of 450 nm?

erastova [34]

Answer

a)Given,

Wavelength of blue light = 450 n m = 450 x 10⁻⁹ m

Speed of light = 3 x 10⁸ m/s

we know,

$c = \nu \lambda$