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
Oduvanchick [21]
3 years ago
5

Imagine that you are working as a roller coaster designer. You want to build a record breaking coaster that goes 70.0 m/s at the

bottom of the first hill. You estimate that the efficiency of the tracks and cars you are using 90.0%. How high must the first hill be?
Physics
1 answer:
Rzqust [24]3 years ago
3 0

Wow !  This is not simple.  At first, it looks like there's not enough information, because we don't know the mass of the cars.  But I"m pretty sure it turns out that we don't need to know it.

At the top of the first hill, the car's potential energy is

                                  PE = (mass) x (gravity) x (height) .

At the bottom, the car's kinetic energy is

                                 KE = (1/2) (mass) (speed²) .

You said that the car's speed is 70 m/s at the bottom of the hill,
and you also said that 10% of the energy will be lost on the way
down.  So now, here comes the big jump.  Put a comment under
my answer if you don't see where I got this equation:

                                   KE = 0.9  PE

        (1/2) (mass) (70 m/s)² = (0.9) (mass) (gravity) (height)     

Divide each side by (mass): 

               (0.5) (4900 m²/s²) = (0.9) (9.8 m/s²) (height)

(There goes the mass.  As long as the whole thing is 90% efficient,
the solution will be the same for any number of cars, loaded with
any number of passengers.)

Divide each side by (0.9):

               (0.5/0.9) (4900 m²/s²) = (9.8 m/s²) (height)

Divide each side by (9.8 m/s²):

               Height = (5/9)(4900 m²/s²) / (9.8 m/s²)

                          =  (5 x 4900 m²/s²) / (9 x 9.8 m/s²)

                          =  (24,500 / 88.2)  (m²/s²) / (m/s²)

                          =        277-7/9    meters
                                  (about 911 feet)
You might be interested in
At which latitude would tropical rain forests be most likely?
Natasha_Volkova [10]
-60 degrees north north north
6 0
3 years ago
I need to find 1).a,b,c
Aleksandr [31]
Let's cut through the weeds and the trash
and get down to the real situation:

                  A stone is tossed straight up at  5.89 m/s .
                  Ignore air resistance.


Gravity slows down the speed of any rising object by  9.8 m/s every second.
So the stone (aka Billy-Bob-Joe) continues to rise for

                     (5.89 m/s / 9.8 m/s²)  =  0.6 seconds.

At that timer, he has run out of upward gas.  He is at the top
of his rise, he stops rising, and begins to fall.

His average speed on the way up is  (1/2) (5.89 + 0) = 2.945 m/s .

Moving for 0.6 seconds at an average speed of  2.945 m/s,
he topped out at

                    (2.945 m/s) (0.6 s) =  1.767 meters above the trampoline.

With no other forces other than gravity acting on him, it takes him
the same time to come down from the peak as it took to rise to it.

   (0.6 sec up) + (0.6 sec down)  =  1.2 seconds until he hits rubber again.



 
5 0
4 years ago
What is an example of gravitational potential to kinetic to electrical current?
Alecsey [184]
Chemical to thermal to electrical current: Burning of coal or natural gases. Gravitational potential to kinetic to electrical current.
6 0
3 years ago
To get a feeling for inertial forces discuss the familiar cases of accelerating in a car in a straight line while increasing or
inn [45]

Answer:

Explanation:

When we accelerate in a car on a straight path we tend to lean backward because our lower body part which is directly in contact with the seat of the car gets accelerated along with it but the upper the upper body experiences this force  later on due to its own inertia. This force is accordance with Newton's second law of motion and is proportional to the rate of change of momentum of the upper body part.

Conversely we lean forward while the speed decreases and the same phenomenon happens in the opposite direction.

While changing direction in car the upper body remains in its position due to inertia but the lower body being firmly in contact with the car gets along in the direction of the car, seems that it makes the upper body lean in the opposite direction of the turn.

On abrupt change in the state of motion the force experienced is also intense in accordance with the Newton's second law of motion.

7 0
3 years ago
Which single force acts on an object in free fall
ICE Princess25 [194]

Answer:

gravity

Explanation:

4 0
3 years ago
Read 2 more answers
Other questions:
  • The fastest speed ever measured for a tennis ball served by a player was 263 km/h. The distance of the tennis court from one end
    5·1 answer
  • Which three elements have strong magnetic properties?
    7·2 answers
  • А
    10·1 answer
  • An aluminum alloy rod has a length of 6.3243 cm at 16.00°C and a length of 6.3568 cm at the boiling point of water. (a) What is
    15·1 answer
  • What is the force that acts against motion
    10·1 answer
  • A 2.2 kg object is whirled in a vertical circle whose radius is 1.0 m. If the time of one revolution is 0.97 s,
    7·1 answer
  • An initially motionless test car is accelerated uniformly to 120 km/h in 8.28 s before striking a simulated deer. The car is in
    15·1 answer
  • 1. A satellite (mass = 4.44 x 109 kg) travels in orbit around the Earth at a distance of 1.9 x 10'm above
    15·1 answer
  • HELP ASAPP!!!! WILL GIVE BRAINLIEST!<br> Describe the chemical structure of a cell membrane
    7·2 answers
  • If an object is accelerating at a rate of 8 m/s^2 what is the mass of the box. <br><br> See attached
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!