All categories

2 years ago

Help 10 points!

Physics

1 answer:

adell [148]2 years ago

3 0

chemical energy into mechanical energy as well as heat.

You might be interested in

An engine draws energy from a hot reservoir with a temperature of 1250 K and exhausts energy into a cold reservoir with a temper

dimulka [17.4K]

Answer:

The power output of this engine is $P = 17.5 W$

The the maximum (Carnot) efficiency is $\eta_c = 0.7424$

The actual efficiency of this engine is $\eta _a = 0.46$

Explanation:

From the question we are told that

The temperature of the hot reservoir is $T_h = 1250 \ K$

The temperature of the cold reservoir is $T_c = 322 \ K$

The energy absorbed from the hot reservoir is $E_h = 1.37 *10^{5} \ J$

The energy exhausts into cold reservoir is $E_c = 7.4 *10^{4} J$

The power output is mathematically represented as

$P = \frac{W}{t}$

Where t is the time taken which we will assume to be 1 hour = 3600 s

W is the workdone which is mathematically represented as

$W = E_h -E_c$

substituting values

$W = 63000 J$

$P = \frac{63000}{3600}$

$P = 17.5 W$

The Carnot efficiency is mathematically represented as

$\eta_c = 1 - \frac{T_c}{T_h}$

$\eta_c = 1 - \frac{322}{1250}$

$\eta_c = 0.7424$

The actual efficiency is mathematically represented as

$\eta _a = \frac{W}{E_h}$

substituting values

$\eta _a = \frac{63000}{1.37*10^{5}}$

$\eta _a = 0.46$

7 0

3 years ago

You are pushing a 60 kg block of ice across the ground. You exert a constant force of 9 N on the block of ice. You let go after

kotykmax [81]

Answer: d = 33 cm or 0.33 m

Explanation: In physics, Work is the amount of energy transferred to an object to make it move. It can be expressed by:

W = F.d.cosθ

F is the force applied to the object, d is the displacement and θ is the angle formed between the force and the displacement.

For the ice block, the angle is 0, i.e., force and distance are at the same direction, so:

W = F.d.cos(0)

W = F.d

To determine d:

d = $\frac{W}{F}$

d = $\frac{3}{9}$

d = 0.33 m

The distance d the block ice moved is 33 cm.

7 0

2 years ago

A wave is travelling at 3000 m/s has a wavelength of 1 m.

Levart [38]

Answer:

a] 3000hz

b]3.33 × 10⁻⁴

ci]300

ii] 3000

iii]60,000

Explanation:

3 0

2 years ago

A driver must always stop within 50 ft but not less than ____________ ft from the nearest rail when the signal is flashing and t

k0ka [10]

Answer:

20 ft

Explanation:

5 0

2 years ago

Read 2 more answers

A block of wood is 4 cm wide, 5 cm long, and 10 cm high. It weighs 100 grams. Calculate its volume. Calculate its density. Will

77julia77 [94]

Answer:

$V=200cm^3\\\\\rho =0.500g/cm^3$

It will float.

Explanation:

Hello.

In this case, given the width, length and height, we can compute the volume as follows:

$V=W*L*H\\\\V=4cm*5cm*10cm\\\\V=200cm^3$

Moreover, since the density is computed via the division of the mass by the volume:

$\rho =\frac{m}{V}$

We obtain:

$\rho =\frac{100g}{200cm^3} \\\\\rho =0.500g/cm^3$

In such a way, since the solid has a lower density than the water, we infer it will float.

Best regards.

3 0

3 years ago