All categories

3 years ago

A perpetual-motion machine can never be built because it is not possible to eliminate...

Physics

2 answers:

bazaltina [42]3 years ago

4 0

The answer is: [C]: "elasticity" .
________________________________________

kykrilka [37]3 years ago

4 0

Answer:

D) Friction

Explanation:

Perpetual Motion machine is that machine which will convert whole input energy into useful work.

So we will say that perpetual motion machine is an hypothetical machine which will be 100% efficient and it will convert whole input energy into useful work without any loss of energy.

we know that efficiency is given as

$efficiency = \frac{output}{Input}$

So in real conditions it is not possible to eliminate frictional force due to which we will not able to get 100% useful work so here in real conditions the efficiency is always less than 100%

so correct answer will be

D) Friction

You might be interested in

A cat climbs 10 m directly up a tree.

Harman [31]

<span>there is no horizontal displacement if he went straight up

straight up means vertical, so his vertical displacment is 20 m</span>

6 0

3 years ago

Do any of the atom diagrams below represent atoms of the same element?

sergeinik [125]

Atom A and atom C are the same element.

6 0

3 years ago

According to recent typical test data, a Ford Focus travels 0.240 mi in 19.3 s, starting from rest. The same car, when braking f

Anit [1.1K]

Answer:

Explanation:

a )

While breaking initial velocity u = 62.5 mph

= 62.5 x 1760 x 3 / (60 x 60 ) ft /s

= 91.66 ft / s

distance trvelled s = 150 ft

v² = u² - 2as

0 = 91.66² - 2 a x 150

a = - 28 ft / s²

b ) While accelerating initial velocity u = 0

distance travelled s = .24 mi

time = 19.3 s

s = ut + 1/2 at²

s is distance travelled in time t with acceleration a ,

.24 = 0 + 1/2 a x 19.3²

a = .001288 mi/s²

= 2.06 m /s²

c )

If distance travelled s = .25 mi

final velocity v = ? a = .001288 mi / s²

v² = u² + 2as

= 0 + 2 x .001288 x .25

= .000644

v = .025 mi / s

= .0025 x 60 x 60 mi / h

= 91.35 mph .

d ) initial velocity u = 59 mph

= 86.53 ft / s

final velocity = 0

acceleration = - 28 ft /s²

v = u - at

0 = 86.53 - 28 t

t = 3 sec approx .

4 0

3 years ago

What is an RC circuit?

cupoosta [38]

Is a circuit with both a resistor (R) and a capacitor (C). RC circuits are frequent element in electronic devices. They also play an important role in the transmission of electrical signals in nerve cells.

Hope this helps!

8 0

3 years ago

The common value for the speed of light in a vacuum is:

OLEGan [10]

The common value for “Speed of light in vacuum” is $\bold{3 \times 10^{8}}$ metre per second.

Answer: Option b

<u>Solution: </u>

Speed of light can be defined as the speed with which light waves propagate in different medium. In vacuum, speed of light is 186,282 miles per second or 299,792 km/s which is rounded off as $3 \times 10^{8} \mathrm{m} / \mathrm{s}$ .

“Speed of light in vacuum” is a universal constant and usually represented by ‘c’. Light waves travels at a speed of $3 \times 10^{8}$ metre per second in vacuum.

5 0

4 years ago