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3 years ago

A river does 6500 J of work on a water wheel every second. The wheels efficiency is 12%

1 answer:

3 0

The power output is 6500 J - ( 12% of 6500 J)

= 5460 J .

Is the first question complete? Because the work done by the river would be equal to work done by the axle of the wheel.

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The length of the track itself is 500m. The vehicles (each of mass 15kg) are dragged

gogolik [260]

Answer:

W = 100000 J = 100 KJ

Explanation:

Here we will use the most basic and general formula of work, which is as follows:

$W = Fd$

where,

W = Work Done = ?

F = Force Required = 200 N

d = Length of Track = 500 m

Therefore,

$W = (200\ N)(500\ m)\\$

5 0

3 years ago

Which of the following phenomena are due to the electric interaction? (Select all that apply.) surface tension in water friction

Eddi Din [679]

Answer:

Surface tension in water

Friction between tires and pavement

Dissolution of salt in water

Explanation:

Surface tension in water: It is due to the electrostatic force of attraction (cohesive force) between water molecules.

Friction between tires and pavement: It is due to the attractive force between tires and pavement.

Dissolution of salt in water: The ions of $Na ^ +$ and $Cl ^ -$ separate due to the strong attraction of water molecules.

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3 years ago

The greater the of an object the more force is needed to cause acceleration

d1i1m1o1n [39]

the greater the <u>mass</u> of an object the more force is needed to cause acceleration

8 0

4 years ago

An object at 27°C has its temperature increased to 37°C.

Firlakuza [10]

Answer:

b. 14

Explanation:

$T_{i}$ = Initial temperature = 27 °C = 27 + 273 = 300 K

$T_{f}$ = Final temperature = 37 °C = 37 + 273 = 310 K

$P_{i}$ = Initial Power radiated by the object

$P_{f}$ = Final Power radiated by the object

We know that the power radiated is directly proportional to fourth power of the temperature. hence

$\frac{P_{f}}{P_{i}} = \frac{T_{f}^{4} }{T_{i}^{4} }\\\frac{P_{f}}{P_{i}} = \frac{(310)^{4} }{(300)^{4} }\\\frac{P_{f}}{P_{i}} = 1.14\\P_{f} = (1.14) P_{i}$