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
Snowcat [4.5K]
3 years ago
13

a.Calculate the average speed (in km/h) of Charlie, who runs to the store 4 kilometers away in 30 minutes. b.Calculate the dista

nce (in km) that Charlie runs if he maintains this average speed for 1 hour
Physics
1 answer:
sveta [45]3 years ago
7 0

as per the question charlie runs to the store which is  4 km away

hence the total distance covered [S] is 4 km

he takes 30 minutes to reach the store.

hence the total time taken [t] = 30 minutes=0.5 hour

We have to calculate the average speed.

the average speed[v]= =\frac{S}{t}

                                   =\frac{4 km}{0.5 hour}

                                    =8 km/hour

then we have to calculate the total distance traveled by charlie in 1 hour.

the distance covered S= V_{avg} *t

                                      =8 km/hour ×1 hour

                                      =8 km

Hence the average speed of charlie is 8 km/hour and he covers a distance of 8 km in 1 hour.

You might be interested in
A heat engine accepts 200,000 Btu of heat from a source at 1500 R and rejects 100,000 Btu of heat to a sink at 600 R. Calculate
diamong [38]

To solve the problem it is necessary to apply the concepts related to the conservation of energy through the heat transferred and the work done, as well as through the calculation of entropy due to heat and temperatra.

By definition we know that the change in entropy is given by

\Delta S = \frac{Q}{T}

Where,

Q = Heat transfer

T = Temperature

On the other hand we know that by conserving energy the work done in a system is equal to the change in heat transferred, that is

W = Q_{source}-Q_{sink}

According to the data given we have to,

Q_{source} = 200000Btu

T_{source} = 1500R

Q_{sink} = 100000Btu

T_{sink} = 600R

PART A) The total change in entropy, would be given by the changes that exist in the source and sink, that is

\Delta S_{sink} = \frac{Q_{sink}}{T_{sink}}

\Delta S_{sink} = \frac{100000}{600}

\Delta S_{sink} = 166.67Btu/R

On the other hand,

\Delta S_{source} = \frac{Q_{source}}{T_{source}}

\Delta S_{source} = \frac{-200000}{1500}

\Delta S_{source} = -133.33Btu/R

The total change of entropy would be,

S = \Delta S_{source}+\Delta S_{sink}

S = -133.33+166.67

S = 33.34Btu/R

Since S\neq   0 the heat engine is not reversible.

PART B)

Work done by heat engine is given by

W=Q_{source}-Q_{sink}

W = 200000-100000

W = 100000 Btu

Therefore the work in the system is 100000Btu

4 0
3 years ago
A 1.5m long string weighs 0.0020 kg. It is tensioned to 100N. A disturbance travels along it with a wavelength of 1.5m, find:a)
Zigmanuir [339]

Answer:

the propagation velocity of the wave is 274.2 m/s

Explanation:

Given;

length of the string, L = 1.5 m

mass of the string, m = 0.002 kg

Tension of the string, T = 100 N

wavelength, λ = 1.5 m

The propagation velocity of the wave is calculated as;

v = \sqrt{\frac{T}{\mu} } \\\\\mu \ is \ mass \ per \ unit \ length \ of \ the \ string\\\\\mu = \frac{0.002 \ kg}{1.5 \ m} = 0.00133 \ kg/m\\\\v = \sqrt{\frac{100}{0.00133} } \\\\v = 274.2 \ m/s

Therefore, the propagation velocity of the wave is 274.2 m/s

7 0
2 years ago
Many processes help to shape Earth’s surface. Starting with a rock, in what order would you expect the following Earth processes
GuDViN [60]
<span>Like most Earth materials, rocks are created and destroyed in cycles. The rock cycle is a model that describes the formation, breakdown, and reformation of a rock as a result of sedimentary, igneous, and metamorphic processes. </span><span>All rocks are made up of minerals. A mineral is defined as a naturally occurring, crystalline solid of definite chemical composition and a characteristic crystal structure. A rock is any naturally formed, nonliving, firm, and coherent aggregate mass of solid matter that constitutes part of a planet. i don't know if this is right but i hope it helps</span>
3 0
3 years ago
Why was the microscope and its improvement an important part of the development of the cell theory?
Tresset [83]

Answer:it’s is part of the cell theory because they where studying cells and to see it you need a microscope

Explanation:basically in the answer area

7 0
2 years ago
Read 2 more answers
Wavelength is measured in hertz true or false?
g100num [7]
Wavelength is measured in various units of distance (mm, cm, m, etc.). Frequency uses hertz, but that is not what the question is asking. Therefore, the answer is false.
3 0
2 years ago
Other questions:
  • Tarzan swings back and forth on a long vine with a period of 7.27 s. how long is the vine?(unit=m)
    9·1 answer
  • Classify Use periodic table to classify the elements potassium (K) ,Bromine (Br) and argon, (Ar) according to know likely their
    6·1 answer
  • If I push on a wall with a force of 3500 N for 5 hours but the wall does not move, how much work have I done.
    9·1 answer
  • Leila is building an aluminum-roofed shed in her backyard to store her garden tools.The flat roof will measure 2.0 x 3.0m in are
    13·1 answer
  • Eight joules of work is required to stretch a spring 0.5 meter from its natural length. Find the work required to stretch the sp
    14·1 answer
  • A fisherman is fishing from a bridge and is using a "42.0-N test line." In other words, the line will sustain a maximum force of
    8·1 answer
  • To completely describe the motion of an object, you need
    9·1 answer
  • An architect is redesigning a rectangular room on the blueprints of a house. She decides to double the width of the room, increa
    11·1 answer
  • A fairgrounds ride spins its occupants inside a flying saucer-shaped container. If the horizontal circular path the riders follo
    9·1 answer
  • A large glass marble is added to the displacement can. 20 3 of water overflows into a beaker, and the displacement can now has a
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!