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3 years ago

If a system requires 150 j of input work and produces 123 J of output work, whats its effiency

1 answer:

4 0

The effiency of a machine is

(output work or energy) / (input work or energy) .

For the system described in the question, that's

(123 J) / (150 J) = 0.82 = 82% .

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A 3.0-kg brick rests on a perfectly smooth ramp inclined at 34° above the horizontal. The brick is kept from sliding down the pl

Firdavs [7]

Answer:

d=0.137 m ⇒13.7 cm

Explanation:

Given data

m (Mass)=3.0 kg

α(incline) =34°

Spring Constant (force constant)=120 N/m

d (distance)=?

Solution

F=mg

F=(3.0)(9.8)

F=29.4 N

As we also know that

Force parallel to the incline=FSinα

F=29.4×Sin(34)

F=16.44 N

d(distance)=F/Spring Constant

d(distance)=16.44/120

d(distance)=0.137 m ⇒13.7 cm

4 0

3 years ago

The weight of a body of certain mass becomes zero in space.why?write with reasons

Anvisha [2.4K]

Answer:

Weight is what you get when a certain amount of gravity is acting on that mass, and something, like the surface of a planet, is resisting that action. In space, when falling freely, there's nothing resisting the pull of gravity so weight disappears. Mass however stays.

hope this helps u

Explanation:

7 0

3 years ago

When a current of 0.015 A passes through human body at 240 volts p.d it<br><br>causes

geniusboy [140]

Explanation:

Given that,

Current, I = 0.015 A

Voltage, V = 240 volts

We need to find the resistance. Using Ohm's law we can find it as follows :

$V=IR\\\\R=\dfrac{V}{I}\\\\R=\dfrac{240}{0.015}\\\\R=16000\ \Omega$

So, When a current of 0.015 A passes through human body at 240 volts p.d it causes 16000 ohms of resistance.

3 0

3 years ago

Hartman value profile

Grace [21]

What is your question exactly? I'm confused?

6 0

4 years ago

A circular loop of flexible iron wire has an initial circumference of 165cm , but its circumference is decreasing at a constant

ArbitrLikvidat [17]

Answer:

emf induced is 0.005445 V and direction is clockwise because we can see area is decrease and so that flux also decrease so using right hand rule direction of current here clockwise

Explanation:

Given data

initial circumference = 165 cm

rate = 12.0 cm/s

magnitude = 0.500 T

tome = 9 sec

to find out

emf induced and direction

solution

we know emf in loop is - d∅/dt ........1

here ∅ = ( BAcosθ)

so we say angle is zero degree and magnetic filed is uniform here so that

emf = - d ( BAcos0) /dt

emf = - B dA /dt ..............2

so area will be

dA/dt = d(πr²) / dt

dA/dt = 2πr dr/dt

we know 2πr = c,

r = c/2π = 165 / 2π

r = 26.27 cm

c is circumference so from equation 2

emf = - B 2πr dr/dt ................3

and

here we find rate of change of radius that is

dr/dt = 12/2π = 1.91 $10^{-2}$ cm/s

so when 9.0s have passed that radius of coil = 26.27 - 191 (9)

radius = 9.08 $10^{-2}$ cm

so now from equation 3 we find emf

emf = - (0.500 ) 2π(9.08 $10^{-2}$ ) 1.91 $10^{-2}$

emf = - 0.005445

and magnitude of emf = 0.005445 V

emf induced is 0.005445 V and direction is clockwise because we can see area is decrease and so that flux also decrease so using right hand rule direction of current here clockwise

4 0

3 years ago