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
Shkiper50 [21]
3 years ago
11

Joe drove at the speed of 45 miles per hour for a certain distance. He then drove at the speed of 55 miles per hour for the same

distance. What is the average speed for the whole trip?
Physics
2 answers:
Oksi-84 [34.3K]3 years ago
8 0

Answer:

47.37 miles per hour,

Explanation:

The average speed is given by the formula

Average speed =(total distance / total time)

Let the distance Joe traveled at a speed of 45 miles per hour be 'D', because he then drove the same distance with a speed of 50 miles per hour then, the total distance is '2D'.

The total time will be the time he drove at a speed of 45 miles per hour (t_{1}) plus the time he drove at a speed of 50 miles per hour (t_{2}).

Then the average speed is :

v_{average} = \frac{2D}{t_{1}+t_{2}}.

Because we know that uniform rectilinear motion is discribed by the ecuation

d=\v*t (where d is distance, v is a constant speed and, t is the time)

we can express both times in terms of speeds and the distance, thus

t_{1} =\frac{D}{v_{1}} and,

t_{2} =\frac{D}{v_{2}}.

So now the average speed v_{average} = \frac{2D}{t_{1}+t_{2}} can be written as follows:

v_{average} = \frac{2D}{(\frac{D}{v_{1}}+\frac{D}{v_{2}} )}

v_{average} = \frac{2D}{D(\frac{1}{v_{1}}+\frac{1}{v_{2}} )}

v_{average} = \frac{2}{(\frac{1}{v_{1}}+\frac{1}{v_{2}} )}

v_{average} = \frac{2}{(\frac{1}{45}+\frac{1}{50} )}

v_{average} = 47.37 miles per hour.

Snowcat [4.5K]3 years ago
5 0

Answer:

v_{avg} = 49.5 mph

Explanation:

Let the distance moved by Joe is "d"

so the time taken by him to drove it by speed 45 mph is given as

t_1 = \frac{d}{v_1}

t_1 = \frac{d}{45}

now the same distance is traveled by him with speed 55 mph

so the time taken by him

t_2 = \frac{d}{55}

so total time taken by him for complete distance 2d

t = t_1 + t_2

t = \frac{d}{45} + \frac{d}{55}

t = 0.0404 d

now the average speed is given as

v_{avg} = \frac{2d}{t}

v_{avg} = \frac{2d}{0.0404d}

v_{avg} = 49.5 mph

You might be interested in
A force of 10 N causes a spring to extend by 20 mm. Find a) the spring constant of the spring in N/m b) the extension of the spr
suter [353]

(a) The spring constant is 500 N/m.

(b) The extension of the spring when 25 N force is applied is 0.05 m.

(c) The applied force to cause an extension of 5 mm is 2.5 N.

The given parameters:

  • Applied force, F = 10 N
  • Extension of the spring, x = 20 mm

The spring constant is calculated as follows;

F = kx\\\\k = \frac{F}{x} \\\\k = \frac{10}{20 \times 10^{-3}} \\\\k = 500 \ N/m

The extension of the spring when 25 N force is applied is calculated as follows;

F = kx\\\\x = \frac{F}{k} \\\\x = \frac{25}{500} \\\\x = 0.05 \ m

The applied force to cause an extension of 5 mm is calculated as follows;

F = kx\\\\F = 500 \times 5 \times 10^{-3}\\\\F = 2.5 \ N

Learn more about Hook's law here: brainly.com/question/12253978

7 0
2 years ago
How do the forces in nuclear and chemical reactions differ?
kvasek [131]

B. Chemical reactions must overcome the strong nuclear force

8 0
3 years ago
Read 2 more answers
What is TRUE of carbon monoxide?
Aleks04 [339]

¡Hello!

Carbon monoxide is an odorless, colorless and tasteless gas produced by the incomplete combustion of carbon in fossil fuels such as wood, propane, charcoal, oil, gas, coal or other fuel.

6 0
2 years ago
2. A body is thrown vertically upward with a speed of 100 m/s.The time taken to be
Pachacha [2.7K]

Answer:

b. 20 sec

Explanation:

y = y₀ + v₀ t + ½ g t²

0 = 0 + (100) t + ½ (-10) t²

0 = 100t − 5t²

0 = t (100 − 5t)

t = 0, t = 20

The body lands after 20 seconds.

4 0
3 years ago
How does friction help soccer players
Lena [83]
When soccer players run they are using friction to propell themselves
7 0
3 years ago
Read 2 more answers
Other questions:
  • 5. An undisturbed soil sample has a wet density of 2.5 Mg/m3 when the water content is 25%. The specific gravity of the soil par
    6·1 answer
  • What can electricty from solar power be used for​
    14·1 answer
  • HEY CAN ANYONE PLS ANSWER THESE QUESTION!!!!!
    5·1 answer
  • HURRY
    9·2 answers
  • How do sports play a role in American Culture? Is this different from how sports play a role in other cultures?
    11·1 answer
  • When the temperature of a gas decreases at constant volume, its a. pressure increases. b. mass increases. c. pressure decreases.
    7·1 answer
  • TIMED! URGENT! REALLY APPRECIATE HELP!! TYSM!!!!!!
    11·2 answers
  • Using your strategy to overcome your obstacle.
    15·2 answers
  • I NEEEED HELPPPPPPP PLEASEEEE
    14·1 answer
  • A pendulum has a mass of 3 kg and is lifted to a height of 0.3 m. What is the maximum speed of the pendulum
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!