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
kupik [55]
3 years ago
9

Please help ASAP. A car engine with a mass of 1750 kg can exert 215 000 W. a) How long will it take the car to reach 95.0 km/h i

f the car is 100% efficient? b) If it actually takes the car 6.5 s to reach 95.0 km/h, what is the efficiency of the car?
Physics
1 answer:
tensa zangetsu [6.8K]3 years ago
5 0
<h2>Answer:</h2><h3><u>QUESTION①)</u></h3>

<em>✔ First step : calculate the kinetic energy that this car requires to reach 95 km/h</em>

95/ 3,6 ≈ 26,4 m/s  

<em>Ec = ½ m x V²  </em>

With Ec in J; m in kg; and V in m/s  

  • Ec = ½ 1750 x 26,4²  
  • Ec ≈ 610 000 J

<em>✔ Knowing that the car has a p power of 215,000 W, so : </em>

T = E/P  

  • T = 610 000/215 000  
  • T ≈ 2.8 s
<h3>The car takes 2.8 s to reach 95 km/h </h3>

<h3><u>QUESTION②)</u></h3>

N = 2,8/6,5 x 100 = 43.07

<h3>The car efficiency is 43 % </h3>
You might be interested in
A 1500 kg car drives around a flat 200-m-diameter circular track at 25m/s. What are the magnitude and direction of the net force
MakcuM [25]

The correct answer to the question is : 9375 N.

CALCULATION:

As per the question, the mass of the car  m = 1500 Kg.

The diametre of the circular track D = 200 m.

Hence, the radius of the circular path R = \frac{D}{2}

                                                                  = \frac{200}{2}\ m

                                                                  = 100 m.

The velocity of the truck v = 25 m/s.

When a body moves in a circular path, the body needs a centripetal force which helps the body stick to the orbit. It acts along the radius and towards the centre.

Hence, the force acting on the car is centripetal force.

The magnitude of the centripetal force is calculated as -

                              Force F = \frac{mv^2}{R}

                                            =  \frac{1500\times (25)^2}{100}\ N

                                            = 9375 N.           [ANS}        

The centripetal force is provided to the car in two ways. It is the friction which provides the necessary centripetal force. Sometimes friction is not sufficient. At that time, the road is banked to some extent which provides the necessary centripetal force.


6 0
3 years ago
Mary cycled at an average speed of 8 km/h. How far has she traveled if she rides for 4 hours?
Sati [7]

Answer:

Which sentence from the passage shows that the function of the river depicted here has carried through to modern times?

Explanation:

Which sentence from the passage shows that the function of the river depicted here has carried through to modern times?

4 0
3 years ago
Read 2 more answers
A children's roller coaster is released from the top of a track. If its maximum speed at ground level is 3 m/s, find the height
san4es73 [151]

Answer:

h = 0.46 m

Explanation:

According to the law of conservation of energy:

Potential Energy Lost by Roller Coaster = Kinetic Energy Gained by Roller Coaster

mgh = \frac{1}{2}mv^2\\\\2gh = v^2\\\\h = \frac{v^2}{2g}

where,

h = height = ?

v = speed at bottom = 3 m/s

g = acceleration due to gravity = 9.81 m/s²

Therefore,

h = \frac{(3\ m/s)^2}{(2)(9.81\ m/s^2)}

<u>h = 0.46 m</u>

4 0
3 years ago
The current theory of the structure of the
IRISSAK [1]

1) The mass of the continent is 3.3\cdot 10^{21} kg

2) The kinetic energy of the continent is 624 J

3) The speed of the jogger must be 4 m/s

Explanation:

1)

We start by finding the volume of the continent. We have:

L = 5850 km = 5.85\cdot 10^6 m is the side

t = 35 km = 3.5\cdot 10^4 m is the depth

So the volume is

V=L^2 t = (5.85\cdot 10^6)^2 (3.5\cdot 10^4)=1.20\cdot 10^{18} m^3

We also know that its density is

d=2750 kg/m^3

Therefore, we can find the mass by multiplying volume by density:

m=dV=(2750)(1.20\cdot 10^{18})=3.3\cdot 10^{21} kg

2)

The kinetic energy of the continent is given by:

K=\frac{1}{2}mv^2

where

m=3.3\cdot 10^{21} kg is its mass

v = 3.2 cm/year is the speed

We have to convert the speed into m/s. We have:

3.2 cm = 0.032 m

1 year = 1(365)(24)(60)(60)=3.15\cdot 10^7 s

So, the speed is:

v=\frac{0.032 m}{3.15 \cdot 10^7 s}=1.02\cdot 10^{-9} m/s

So, we can now find the kinetic energy:

K=\frac{1}{2}(1.20\cdot 10^{21})(1.02\cdot 10^{-9})^2=624 J

3)

Here we have a jogger of mass

m = 78 kg

And the jogger has the same kinetic energy of the continent, so

K = 624 J

The kinetic energy of the jogger is given by

K=\frac{1}{2}mv^2

where v is the speed of the jogger.

Solving for v, we find the speed that the jogger must have:

v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(624)}{78}}=4 m/s

Learn more about kinetic energy:

brainly.com/question/6536722

#LearnwithBrainly

3 0
3 years ago
Jerome is learning how the model of the atom has changed over time as new evidence was gathered. He has images of four models of
Stolb23 [73]

Answer:

Y, X, Z, W

Explanation:

You know W is the most recent because it features the nucleus in the middle and the electron cloud which was shown in models after the others.

5 0
3 years ago
Read 2 more answers
Other questions:
  • Where are the magnetic field and force weakest in a magnet?
    11·1 answer
  • Recall the topography of the Sierra Nevada Mountains east of California's central valley. Which of the following locations would
    5·1 answer
  • The voltage applied across a given parallel-plate capacitor is doubled. How is the energy stored in the capacitor affected?
    6·1 answer
  • Can water boil at 0°?
    10·1 answer
  • One advantage of the __________ model is quick recognition. A. prototype B. exemplar C. language D. concept Please select the be
    9·1 answer
  • 2. How can we make the percent error value as minimal as possible?
    14·2 answers
  • Most energy obtained from water is converted from _____.
    9·2 answers
  • Which is NOT something that all green plants have in common?
    6·2 answers
  • A student made the electromagnet shown and used it to pick up one sewing pin. She
    14·2 answers
  • Heat always transfers from substances with _____ thermal energy to substances with _______ thermal until both substances reach t
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!