In your everyday life you come across a range of motions in which

A heat engine performs (245 + A) J of work in each cycle while also delivering (142 + B) J of heat to the cold reservoir. Find t

Ganezh [65]

Answer:

The value is $\eta = 54.4 \%$

Explanation:

From the question we are told that

The work input is $W = ( 245 + A ) \ J$

The heat delivered is $Q = (142 + B) \ J$

The value of A is A = 14

The value of B is B = 72

Generally the efficiency of the heat engine is mathematically represented as

$\eta = \frac{W}{Q_t}$

Here $Q_t$ is the total out energy produce by the heat engine and this is mathematically represented as

$Q_t= Q + W$

=> $Q_t= 245 + A + 142 + B$

=> $Q_t= 390 + A+B$

So

$\eta = \frac{245 + A }{390 + A+ B}$

=> $\eta = 0.544$

=> $\eta = 0.544 *100$

=> $\eta = 54.4 \%$

5 0

2 years ago

Given a 10-V power supply, would a 20-ohm resistor and a 5-ohm resistor need to be arranged in parallel or in series to generate

Bogdan [553]

Answer:

The resistors will be in parallel to produce a net resistance of 4ohm and current in 20 ohm resistor will be 0.5A and 5ohm resistor will be 2A.

Explanation:

We are given 10 voltage power source and we have two Resistors with resistance of 20 ohm and 5ohm.

We need to find the orientation in which these two resistors would be arranged so that the circuit could get a current of 2.5Ampere.

Using ohm's law we have

V = I*R

V= voltage

I= current

R= resistance

10 = 2.5*R

R = 10/2.5 = 4ohm

that means we need a total of 4ohm resistance from these two resistors.

since the net Resistance(4ohm) is lower than the smallest resistance(5ohm) available that means the orientation of the resistors will be in parallel.

$\frac{1}{R} = \frac{1}{R1} +\frac{1}{R2}\\ = \frac{1}{20} +\frac{1}{5}\\ \\ = \frac{1+4}{20} =\frac{1}{4}$

R(net) =4ohm

Now the orientation of the resistors are in parallel so the current will be divided.

we know that the current will divide in opposite manner the arm which provides more resistance less current will flow from there and vice versa.

We know that the voltage in parallel remains same

In 20 ohm resistance

again using ohms law

V = i1*R1

10 = i1*20

i1 = 0.5A

in 5ohm resistor

V=i2*R2

10 = I2*5

i2 =2A

and i1+i2 = 0.5+2= 2.5A which means our calculation is correct.

Therefore the resistors will be in parallel to produce a net resistance of 4ohm and current in 20 ohm resistor will be 0.5A and 5ohm resistor will be 2A.

6 0

2 years ago

What is the mass, in grams, of a pure iron cube that has a volume of 3.70cm cubed?

Arlecino [84]

To determine the amount in grams of the iron, we need data on the density of iron. From literature, it has a value of <span>p=7.9 g/cm3. We simply multiply the volume to the density. We do as follows:

mass = 3.70 (7.9) = 29.23 g Fe

Hope this answers the question. Have a nice day.</span>

7 0

3 years ago

An oscilloscope shows a steady sinusoidal signal of 5 Volt peak to peak, which spans 5 cm in vertical direction on the screen. B

Troyanec [42]

Answer:

it will show a continuous rise in value. The rise will be sinusoidal.

Explanation:

3 0

3 years ago

A centrifuge is a device used to separate materials by their masses. A sample in a centrifuge is rotated at high speeds along a

german

Answer:

F = 1.047 10⁻² N

Explanation:

Let's use kinematics to find the angular acceleration

w = w₀ + α t

as for rest w₀ = 0

w = α t

α = w / t

let's reduce the magnitudes to the SI system

w = 1000 rev / min (2π rad/ 1 rev) (1 min/ 60s) = 104.72 rad / s

m = 1.00 g (1 kg / 1000 g) = 1,000 10⁻³ kg

r = 10.0 cm (1 m / 100 cm) = 0.100 m

let's calculate

α = 104.72 / 1

α = 104.72 rad / s²

angular and linear variables are related

a = α r

a = 104.72 0.100

a = 10.47 m / s²

finally we substitute in Newton's second law

F = 1 10⁻³ 10.47

F = 1.047 10⁻² N

8 0

3 years ago