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
pychu [463]
3 years ago
8

A train travels 120 km at a speed of 60 km/h, makes a stop for 0.5 h, and then travels the next 180 km at a speed of 90 km/h. Wh

at is the average speed of the train for this trip?
Physics
1 answer:
Ludmilka [50]3 years ago
6 0

<u>The average speed</u> of the train for the trip is equal to 66.67\frac{km}{h}

Why?

To calculate the average speed, we need to divide the trip into three moments:

- First moment, the train traveled 120 km at a speed of 60 km/h.

- Second moment, the train stopped for 0.5 hours, meaning that the train did not travel for that time (traveled distance equal to 0 km).

- Third moment, the train traveled 180 km at a speed of 90 km/h.

We can use the following formula to calculate the average speed:

AverageSpeed=\frac{TotalDistance}{TotalTime}

So, for our problem we have:

AverageSpeed=\frac{distance_{1}+distance_{2}+distance{3}}{time_{1}+time_{2}+time_{3}}

From the statement, we know that:

distance_{1}=120km\\speed_{1}=60\frac{km}{h}\\\\distance_{2}=0km\\time_{2}=0.5hours\\\\distance_{3}=180km\\speed_{1}=90\frac{km}{h}\\

Calculating the times, we have:

speed=\frac{distance}{time}\\\\time=\frac{distance}{speed}

time_{1}=\frac{distance_{1}}{speed_{1}}=\frac{120km}{60\frac{km}{h}}=2hours

time_{3}=\frac{distance_{3}}{speed_{3}}=\frac{180km}{90\frac{km}{h}}=2hours

Then, substituting the times into the main equation, we have:

AverageSpeed=\frac{120km+0km+180km}{2hours+0.5hours+2hours}=\frac{300km}{4.5hours}=66.67\frac{km}{h}

Hence, we have that <u>the average speed</u> of the train for the trip is equal to 66.67\frac{km}{h}

Have a nice day!

You might be interested in
The roller-coaster car shown in fig. 6-41 (h1 = 30 m, h2 = 12 m, h3 = 20 m), is dragged up to point 1 where it is released from
maxonik [38]
<span>Since there is no friction, conservation of energy gives change in energy is zero Change in energy = 0 Change in KE + Change in PE = 0 1/2 x m x (vf^2 - vi^2) + m x g x (hf-hi) = 0 1/2 x (vf^2 - vi^2) + g x (hf-hi) = 0 (vf^2 - vi^2) = 2 x g x (hi - hf) Since it starts from rest vi = 0 Vf = squareroot of (2 x g x (hi - hf)) For h1, no hf Vf = squareroot of (2 x g x (hi - hf)) Vf = squareroot of (2 x 9.81 x 30) Vf = squareroot of 588.6 Vf = 24.26 For h2 Vf = squareroot of (2 x 9.81 x (30 – 12)) Vf = squareroot of (9.81 x 36) Vf = squareroot of 353.16 Vf = 18.79 For h3 Vf = squareroot of (2 x 9.81 x (30 – 20)) Vf = squareroot of (20 x 9.81) Vf = 18.79</span>
7 0
3 years ago
What is meant by heat energys​
ad-work [718]

Answer:

heat energy is the form of energy produced by heat

when we burn heat a type of enery is came

4 0
2 years ago
How long will it take a plane to fly 1256km<br> if it travels 500km/hr?
expeople1 [14]

Answer:

<h3>The answer is 2.51 s</h3>

Explanation:

The time taken can be found by using the formula

t =  \frac{d}{v}  \\

d is the distance

v is the velocity

From the question we have

t =  \frac{1256}{500}  \\  = 2.512

We have the final answer as

<h3>2.51 s</h3>

Hope this helps you

4 0
2 years ago
After the driver first notices the obstacle, the car moves uniformly for a time interval t1−t0=t before the brakes are applied.
loris [4]

Answer:

V(t1-t0)

Explanation:

Moving 'uniformly' means constant velocity (speed). the formula for constant speed motion is V = \frac{distance}{time} =( change in position/ change in time)

where,

                  V is speed

given in the statement :

change in time = t =  t1-t0

let the constant speed be ' V '

disance = X = X1-X0

applying the above mentioned formula: V = \frac{X}{t}

V = X/t

X = Vt

the distance X1-X0 = Vt =V(t1-t0)

3 0
3 years ago
What's the airplane velocity when it flies 100 miles in 20 seconds<br><br>​
Allushta [10]

Answer : 5m/s

Explanation:the formular for velocity is distance /time or you can say displacement /time. Then it would then be

100/20 =5m/s

3 0
3 years ago
Read 2 more answers
Other questions:
  • Which state of matter has particles with the greatest amount of kinetic energy?
    9·1 answer
  • A visitor to a lighthouse wishes to determine the height of the tower. She ties a spool of thread to a small rock to make a simp
    7·1 answer
  • Calculate the potential energy of a rock that has a 45 kg mass and is sitting
    6·1 answer
  • HALP MEH! 50 PTS!!!!
    12·2 answers
  • A body is found in the woods and all you have left to analyze are bones and teeth. Explain what isotopes would be helpful to you
    12·1 answer
  • If a converging lens forms a real, inverted image 24.0 cm to the right of the lens when the object is placed 48.0 cm to the left
    6·2 answers
  • A particle initially located at the origin has an acceleration of = 2.00ĵ m/s2 and an initial velocity of i = 8.00î m/s. Find (a
    7·1 answer
  • The amount of force needed to keep a 0.1 kg basketball moving at a constant speed of 6 m/s on frictionless ice is how much N?
    12·1 answer
  • A wire of length 40 cm and area of cross -section 0.1 mm² has a resistance of 0.8Ω. Calculate specific resistance of the wire.​
    12·1 answer
  • Suppose a child swings around her straight arm about her shoulder joint at an angular velocity of 13 rad/s. If her arm is 40. 0
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!