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3 years ago

A perpetual-motion machine can never be built because it is not possible to eliminate...

Physics

2 answers:

bazaltina [42]3 years ago

4 0

The answer is: [C]: "elasticity" .
________________________________________

kykrilka [37]3 years ago

4 0

Answer:

D) Friction

Explanation:

Perpetual Motion machine is that machine which will convert whole input energy into useful work.

So we will say that perpetual motion machine is an hypothetical machine which will be 100% efficient and it will convert whole input energy into useful work without any loss of energy.

we know that efficiency is given as

$efficiency = \frac{output}{Input}$

So in real conditions it is not possible to eliminate frictional force due to which we will not able to get 100% useful work so here in real conditions the efficiency is always less than 100%

so correct answer will be

D) Friction

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3 years ago

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Klio2033 [76]

Answer: v = 0.6 m/s

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Momentum is calculated as Q = m.v

For the piñata problem:

$Q_{i}=Q_{f}$

$m_{p}v_{p}_{i}+m_{s}v_{s}_{i}=m_{p}v_{p}_{f}+m_{s}v_{s}_{f}$

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After the collision, the stick stops, so $v_{s}_{f}=0$ .

Rearraging, we have:

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Substituting:

$v_{p}_{f}=\frac{(0.54)(4.8)}{(4.4)}$

$v_{p}_{f}=$ 0.6

Immediately after being cracked by the stick, the piñata has a swing speed of 0.6 m/s.

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3 years ago

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Answer:

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3 years ago

Read 2 more answers

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Alexus [3.1K]

Answer:

1. balanced

2. unbalanced

3. balanced

4. balanced

5. unbalanced

6. unbalanced

7. unbalanced

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3 years ago

If a horse does 4000 J of work over 20 m, how much force does the horse use?

astraxan [27]

In physics, a force is said to do work if, when acting, there is a displacement of the point of application in the direction of the force. It is calculated by the formula W = f x d. Therefore, we calculate the problem above as follows:

W = f x d
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3 years ago