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3 years ago

Why is the efficiency of a machine always less than 100%?

1 answer:

8 0

Answer:The percentage of the work input that becomes work output is the efficiency of a machine. Because there is always some friction, the efficiency of any machine is always less than 100 percent.

Explanation:

Sub to rockingcoolstyle15 on yt

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______ is an offer to repair or replace a product if there is a problem with the product?

ANTONII [103]

<span>A warranty is an offer to repair or replace a product if there is a problem with the product. Warranties are written guarantee issued to the consumer by the manufacturer at the time of purchase, promising to repair or replace a faulty material. It is usually based on the premise that the product is free from defects in materials and workmanship. It claims that the manufacturer constructed the product out of proper materials, and would compensate the consumer should there be any defects. The period to file a claim typically varies. Some manufacturers place a 90 day period, some a year and a few, even more.</span>

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4 years ago

List 3 cases in which potential energy becomes kinetic energy and three cases in which kinetic energy becomes potential energy.

Mrrafil [7]

Answer:

when you open a can of pop

when you jump on your bed

Explanation:

3 0

3 years ago

The deflection of a 160-cm-long beam in bending will be _____ times the deflection of an equivalent 120-cm-long beam.

katovenus [111]

Answer:

Number of time bend length = 1.33 (Approx.)

Explanation:

Given:

Length of beam = 160 centimeter

Length of beam after deflection = 120 centimeter

Find:

Number of time bend length

Computation:

Number of time bend length = Length of beam / Length of beam after deflection

Number of time bend length = 160 / 120

Number of time bend length = 1.33333

Number of time bend length = 1.33 (Approx.)

8 0

3 years ago

The energy released during a nuclear reaction is a result of

astra-53 [7]

Answer:

the conversion of matter into energy

Explanation:

A nuclear reaction is a reaction in which there is a change in the nuclei of the atoms involved. The two most important examples of nuclear reactions are:

- Nuclear fission: it occurs when a heavy, unstable nucleus breaks apart into two or more lighter nuclei

- Nuclear fusion: it occurs when two lighter nuclei fuse together into a heavier nucleus

In both cases, the total mass of the final products is smaller than the total mass of the initial nuclei: this means that part of the mass of the initial nuclei has been converted into energy, according to Einstein's formula:

$E=\Delta m c^2$

where $\Delta m$ is the variation of mass and c is the speed of light. Since the value of c is very large, we can see from the formula that even a small amount of $\Delta m$ is able to produce a huge amount of energy, and this is a typical feature of any nuclear reaction.

8 0

3 years ago

A 4-foot spring measures 8 feet long after a mass weighing 8 pounds is attached to it. The medium through which the mass moves o

aniked [119]

Correct question is;

A 4-foot spring measures 8 feet long after a mass weighing 8 pounds is attached to it. The medium through which the mass moves offers a damping force numerically equal to √2 times the instantaneous velocity. Find the equation of motion if the mass is initially released from the equilibrium position with a downward velocity of 7 ft/s. (Use g = 32 ft/s²)

Answer:

x(t) = 7te^(-2t√2)

Explanation:

We are given;

Weight; W = 8 lbs

mass; m = W/g

g = 32 ft/s²

Thus;

m = 8/32

m = ¼ slugs

From Newton's second law we can write the equation as;

m(d²x/dt²) = -kx - β(dx/dt)

Rearranging this, we have;

(d²x/dt²) + (β/m)(dx/dt) + (k/m)x = 0

Where;

β is damping constant = √2

k is spring constant = W/s

Where s = 8ft - 4ft = 4ft

k = 8/4

k = 2

Thus,we now have;

(d²x/dt²) + (√2/(¼))(dx/dt) + (2/(¼))x = 0

>> (d²x/dt²) + (4√2)dx/dt + 8x = 0

The auxiliary equation of this is;

m² + (4√2)m + 8 = 0

Using quadratic formula, we have;

m1 = m2 = -2√2

The general solution will be gotten from;

x_t = c1•e^(mt) + c2•t•e^(mt)

Plugging in the relevant values gives;

x_t = c1•e^(mt) + c2•t•e^(mt)

At initial condition of t = 0, x_t = 0 and thus; c1 = 0

Also at initial condition of t = 0, x'(0) = 7 and thus;

Since c1 = 0, then c2 = 7

Thus,equation of motion is;

x(t) = 7te^(-2t√2)

8 0

3 years ago