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3 years ago

I would appreciate some help.

1 answer:

4 0

You oughtta be able to do this one.

The "efficiency" is just the portion of the input work that
comes out in a useful form.

If the efficiency is 70%, that tells you that however much work
you put INto the machine, the machine will do 70% of that much
work for you at the output side.

Put 20,000 J in ... out comes (0.70) x (20,000 J) = 14,000 J .

What happens to the other 30% of the work you put into it ?
It turns into HEAT. That's why machines always have to be
cooled somehow while they're running.

You might be interested in

.<br> Why are meteorites moving?

lisov135 [29]

Answer:

Glow

Explanation:

Actually, it is the air in front of the meteoroid that heats up. The particle is traveling at speeds between 20 and 30 kilometers per second. It compresses the air in front, causing the air to get hot. The air is so hot it begins to glow — creating a meteor - the streak of light observed from Earth.

Hope this helped!

7 0

3 years ago

During the compression stroke of an internal combustion engine, _____

Leona [35]

easy, The fuel is ignited

6 0

3 years ago

Jackson ran in a marathon for 3 hours. The marathon was 185 miles long. How fast was the runner running?

boyakko [2]

Answer:

hgt tdyrghgcderhgfe

Explanation:

rghttyhhhggggftttgf d's weyhvfswertfcdsettyhgftgdfvhgg fee e4y

4 0

3 years ago

In a game of pool, the cue ball strikes another ball of the same mass and initially at rest. After the collision, the cue ball m

ikadub [295]

(a) $-39.4^{\circ}$

Let's take the initial direction (before the collision) of the cue ball has positive x-direction.

Along the y-direction, the total initial momentum is zero:

$p_y =0$

Therefore, since the total momentum must be conserved, it must be zero also after the collision. So we write:

$0 = m v_1 sin \phi_1 + m v_2 sin \phi_2 \\0 = m(4.60) sin (28^{\circ}) + m(3.40) sin \phi_2$

where

m is the mass of each ball

$v_1= 4.60 m/s$ is the velocity of the cue ball after the collision

$v_2 = 3.40 m/s$ is the velocity of the second ball after the collision

$\phi_1=28.0^{\circ}$ is the angle of the cue ball with the x-axis

$\phi_2$ is the angle of the second ball

Solving for $\phi_2$ , we find the angle between the direction of motion of the second ball and the original direction of motion:

$sin \phi_2 = -\frac{4.60 sin 28}{3.40}=-0.635\\\phi_2 = -39.4^{\circ}$

(b) 6.69 m/s

To find the original speed of the cue ball, we analyze the situation along the horizontal direction.

First, we calculate the total momentum along the x-direction after the collision, which is:

$p_x = m v_1 cos \phi_1 + m v_2 cos \phi_2 \\0 = m(4.60) cos (28^{\circ}) + m(3.40) cos (-39.4^{\circ})=6.69 m$

The initial total momentum along the x-direction as

$p_x = m u$

where

m is the mass of the cue ball

$u$ is the initial velocity of the cue ball

The momentum along this direction must be conserved, so we can equate the two expressions and find the value of u:

$mu = 6.69 m\\u = 6.69 m/s$

7 0

3 years ago

What is the sum of 9260 and 3240?

Ket [755]

The sum is the result of adding 9260 and 3240 together. Each number can be broken down into constituent parts in order to make addition easier. Each place in the number represents its value, so a 2 in the hundreds place represents 200.
You can separate numbers out this way to make it easier to add them. 9260 can be broken down into 9000+200+60 while 3240 is 3000+200+40. You can then add these six numbers together.

60+40 = 100
200+200 = 400
9000+3000 = 12000

Then add your three partial results together to receive the final answer:

12000+400+100 = 12500

4 0

3 years ago