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3 years ago

Is velocity ratio of a machine affected by applying oil on it?Explain with reason.

1 answer:

6 0

Factors affecting friction

The intensity of friction depends on following factors: i) The area involved in friction. ii) The pressure applied on the surfaces. Force = Pressure ´ Area Frictional force will increase, if the area of contact will increase or if pressure applied on the surface increased.

Methods to reduce friction

i) Polish the contact surface. ii) Put oil or grease so that it fills in the small gaps of the flat parts. iii) Use ball bearings to reduce area of contact between rotating parts.

Lubrication

Following methods can be used to reduce friction: Oil is either thin or viscous. It depends upon SAE No. of oil. (SAE means Society of Automotive Engineers). If we use very viscous oil, it does not reach all the parts. Very thin oil will flows away easily and gets wasted. Grease is used in such cases. It is generally used around ball-bearing. Normal grease or oil is never used where there is high pressure, high temperature and high speed. Special lubricants are used in such cases. In cold season the oil becomes thick and in hot season it becomes thin. Therefore selection of lubrication also depends on the season. It is always advisable to refer operating manual of the equipment before selecting the lubricant.

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___ acceleration occurs when an object speeds up

AleksandrR [38]

Explanation:

Acceleration is defined as the change in velocity over time.

When there is an increment or increase in the magnitude of velocity of a moving body then it is known as positive acceleration.

Whereas when there is a decrease in magnitude of velocity of a moving body then it is known as negative acceleration.

Thus, we can conclude that positive acceleration occurs when an object speeds up.

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3 years ago

Read 2 more answers

150 ml of water is heated with a burning marshmallow From 20 c to 93.5 C

kap26 [50]

93.5 if it’s wrong sorry sis I need my homework done too

7 0

3 years ago

he graph shows the distance (x) traveled by an aircraft traveling at constant velocity in corresponding time intervals (t). What

Feliz [49]

Answer:

B linear, 825 meters

Explanation:

5 0

3 years ago

A 460 W heating unit is designed to operate with an applied potential difference of 120 V (a) By what percentage will its heat o

dybincka [34]

Answer:

(a) = -0.16%

(b) = smaller

Explanation:

given

power = 460 W

potential difference = 120 V

(a) what percentage will its heat output drop if the applied potential difference drops to 110 V ?

we know $p = \frac{v^2}{R}$ .....................(i)

we need to find change in power

$\Delta P = \frac{\Delta (V^2)}{R}$

$\Delta P = \frac{2 V \Delta V}{R}$ ..............(ii)

from equations we get

$\frac{\Delta P}{P} = \frac{2 \Delta V}{V}$

$\frac{\Delta P}{P} = 2 \frac{110 -120}{120}$

$\frac{\Delta P}{P} = -2(\frac{10}{120})$

$\frac{\Delta P}{P} = - 0.16 %$

(b)

if we increase temperature resistance will increase and decrease with decrease in temperature and we know power is inversely proportional to resistance so if potential decrease and it would cause drop in power

and due to this increment of heating power resistance will decrease so actual drop in the power would be smaller

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3 years ago

A hard rubber ball on a string is being used as a pendulum. When you first look at the pendulum, the ball is being held to one s

Wittaler [7]

Answer:

<h2>Total thermal energy for all air molecules is 59.54 J</h2>

Explanation:

As we know that the ball comes to rest finally so here we can say that

initial total potential energy of the ball is transferred to the air molecules

So here we have

$E_{th} = mgh$

$E_{th} = (6.2 kg)(9.8 m/s^2)(0.98 m)$

So here we have

$E_{th} = 59.54 J$

So all the gravitational potential energy of the ball will convert into thermal energy of air molecules which is equal to 59.54 J

4 0

3 years ago

Is velocity ratio of a machine affected by applying oil on it?Explain with reason.​

Is velocity ratio of a machine affected by applying oil on it?Explain with reason.