All categories

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% .

You might be interested in

Consider a pipe of length L that is open at both ends. What are the wavelengths of the three lowest-pitch tones produced by this

lina2011 [118]

Answer:

2 L, L, 2 L/3

Explanation:

For a pipe of length l open at both ends, the length of the pipe is given by :

$l=\dfrac{n\lambda}{2}$

$\lambda=\dfrac{2l}{n}$

For first pitch tone, n = 1

$\lambda_1=2l$

For first pitch tone, n = 2

$\lambda_2=\dfrac{2l}{2}$

$\lambda_2=l$

For first pitch tone, n = 3

$\lambda_3=\dfrac{2l}{3}$

So, the wavelengths of the three lowest-pitch tones produced by this pipe are 2 L, L, 2 L/3 respectively. Hence, the correct option is (d)

8 0

3 years ago

(II) A 0.72-m-diameter solid sphere can be rotated about an axis through its center by a torque of 10.8 m • N which accelerates

kozerog [31]

Answer:

$m = 23.3 kg$

Explanation:

As we know that it will have constant torque on it

so the acceleration of the ball will be constant so here we can say that we can use kinematics equation

$\theta = \omega_i t + \frac{1}{2}\alpha t^2$

$160(2\pi) = 0 + \frac{1}{2}\alpha (15^2)$

$320 \pi = 112.5 \alpha$

so we have

$\alpha = \frac{320\pi}{112.5}$

$\alpha = 8.94 rad/s^2$

now we know that

$\tau = I \alpha$

$10.8 = I(8.94)$

$I = 1.21 kg m^2$

so we know that

$I = \frac{2}{5}mR^2$

here we know that

diameter = 0.72 m

so radius (R) = 0.36 m

$\frac{2}{5}m(0.36^2) = 1.21$

$m = 23.3 kg$

8 0

3 years ago

Consider a car turning about curved path of radius 40 m and banking angle 5 degree without skidding.

Fudgin [204]

Explanation:

speed of curved path=under root of Mew and gravity

smooth surface Mew=0

so under root of 0×g

4 0

3 years ago

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

sveticcg [70]

Need any help, or are you just giving your points away?

5 0

3 years ago

Read 2 more answers

PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!!

Gelneren [198K]

Work = force x distance (displacement) or the change in Kinetic energy

Carrying a box down a corridor has no external force acting on the box and therefore no work is being done.

Pushing against a locked door doesn't displace the door, so no work is being done.

Suspending a heavy weight with a strong chain requires, no force and actually prevents a force from acting on the chain.

Pulling a trailer up a hill on the other hand requires a person to apply a force to the trailer and displace it up the hill and therefore it requires work.

6 0

3 years ago