1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Galina-37 [17]
2 years ago
12

The boy in the wagon begins throwing bricks out of the wagon to simulate rocket propulsion. The wagon begins at rest, and the bo

y throws three bricks. The boy’s weight is 80lbs, and the weight of the wago 20 lbs. The bricks weigh 10 lbs each, and he throws them with a horizontal velocity of 10 ft/s relative to the wagon. Neglect horizontal forces on the wagon's wheels.
A) What velocity does the boy attain if he throws the bricks one at a time?
B) What velocity does the boy attain if he throws all three bricks at once?
C) Compare the results of parts (a) and (b). What does this suggest about rocket propulsion? Why are these results different?
Engineering
1 answer:
Digiron [165]2 years ago
5 0

Q:What velocity does the boy attain if he throws the bricks one at a time?

Answer:Linear velocity since it moves back and firth and does not rotate like angular velocity.

You might be interested in
A large heat pump should upgrade 5 MW of heat at 85°C to be delivered as heat at 150°C. Suppose the actual heat pump has a COP o
AysviL [449]

Answer:

W=2 MW

Explanation:

Given that

COP= 2.5

Heat extracted from 85°C  

Qa= 5 MW

Lets heat supplied at 150°C   = Qr

The power input to heat pump = W

From first law of thermodynamics

Qr= Qa+ W

We know that COP of heat pump given as

COP=\dfrac{Qr}{W}

2.5=\dfrac{5}{W}

2.5=\dfrac{5}{W}

W=2 MW

For Carnot heat pump

COP=\dfrac{T_2}{T_2-T_1}

2.5=\dfrac{T_2}{T_2-(273+85)}

2.5 T₂ -  895= T₂

T₂=596.66 K

T₂=323.6 °C

7 0
3 years ago
Military glorification through mosaics, relief carvings and triumphant arches are often associated with?
emmasim [6.3K]

Military glorification through mosaics, relief carvings and triumphant arches are often associated with roman architectural monument and is the correct choice.

<h3>What is a Monument?</h3>

This can be defined as a structure which is usually large and is used to commemorate the history of an influential person. This helps to serve as an example and also a reminder as to why the performance of good deeds are important

The use of military glorification through mosaics, relief carvings and triumphant arches were also often used by the Romans in other to commemorate war victories and the succession of a new ruler which is known as the emperor.

Read more about Roman monuments here brainly.com/question/15786258

#SPJ1

8 0
2 years ago
If you had a match and a lantern and a candle in the dark which one would you choose to light.
PSYCHO15rus [73]

Answer:

The match

Explanation:

You can light both the lantern and the candle if you light the match first.

I don't know of this is a homework question, but I answered it anyway :)

5 0
3 years ago
Read 2 more answers
For a short time a rocket travels up and to the left at a constant speed of v = 650 m/s along the parabolic path y=600−35x2m, wh
julia-pushkina [17]

Answer:

Detailed working is shown

Explanation:

The attached file shows a detailed step by step calculation..

4 0
3 years ago
Annealing is a process by which steel is reheated and then cooled to make it less brittle. Consider the reheat stage for a 100-m
kodGreya [7K]

Complete question is;

Annealing is a process by which steel is reheated and then cooled to make it less brittle. Consider the reheat stage for a 100 mm thick plate (ρ = 7830 kg/m3, Cp = 550 J/kg K, k = 48 W/m K). The plate initially is at 200 °C and is to be heated to a minimum temperature of 550 °C. Heating is effected in a gas-fired furnace where the products of combustion at T∞ = 800 °C maintain a convection heat transfer coefficient of h = 250 W/m.K on both surfaces of the plate. How long should the plate be left in the furnace?

Answer:

860 seconds

Explanation:

We are given;

Initial Temperature; Ti = 200 °C

Minimum Temperature; T_i = 550 °C

T∞ = 800 °C

convection coefficient; h = 250 W/m².K

ρ = 7830 kg/m³

Cp = 550 J/kg K

k = 48 W/m K

Plate thickness = 100mm

Thus,L = 100/2 = 50mm = 0.05 m

Let's find the biot number from the formula;

Bi = hL/K

Bi = (250 × 0.05)/48

Bi = 0.2604

Now, lowest temperature in the slab is given as;

θ_o = (T_o - T∞)/(T_i - T∞)

θ_o = (550 - 800)/(200 - 800)

θ_o = 0.4167

Now, from online tables calculation, we can find the root of the biot number.

Thus, root of the biot number Bi = 0.2604 is;

ζ1 = 0.488 rad

Also, C1 is gotten as 1.0396

Now,formula for thermal diffusivity is;

α = k/ρc

α = 48/(7830 × 550)

α = 1.115 × 10^(-5) m²/s

Also, from online tables, f(ζ1) = 0.401

Thus, we can find the time the plate should the plate be left in the furnace from;

-(ζ1)²(αt/L²) = In 0.401

-(ζ1)²(αt/L²) = -0.9138

t = (-0.9138 × 0.05²)/-(0.488² × 1.115 × 10^(-5))

t ≈ 860 s

8 0
3 years ago
Other questions:
  • 5. Identify the pros and cons of<br> manufactured siding.
    12·1 answer
  • Which of the following refers to software designed to alter system files and utilities on a victim’s system with the intention o
    15·1 answer
  • g An analog voice signal, sampled at the rate of 8 kHz (8000 samples/second), is to be transmitted by using binary frequency shi
    12·1 answer
  • 1. Pump extracts energy from a flowing fluid. _______
    10·1 answer
  • The output side of an ideal transformer has 35 turns, and supplies 2.0 A to a 24-W device. Ifthe input is a standard wall outlet
    6·1 answer
  • The efficiency of a steam power plant can beincreased by bleeding off some of the steam thatwould normally enter the turbine and
    15·1 answer
  • if stall speed in ktas for an aircraft us 100 ktas at sea level, what is the stall speed in ktas of the aircraft at 5000 ft dens
    7·1 answer
  • What are the nine Historical periods?
    9·1 answer
  • What is anthropology? Discuss the type of anthropology?
    5·2 answers
  • 7. True or False? The positive effects of a new<br> technology always outweigh its negative effects.
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!