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
scZoUnD [109]
3 years ago
8

If a roller coaster car had 40,000 J of gravitational potential energy when at rest on the top of a hill how much kinetic energy

does it have when it is 3/4 of the way down the hill
Physics
1 answer:
Inessa [10]3 years ago
6 0

Answer:

K.E = 30,000 J

Explanation:

Given,

The potential energy of the roller coaster car, P.E = 40000 J

The kinetic energy at height h/4, K.E = ?

According to the law of conservation of energy, the total energy of the system is conserved.

At height 'h', the total energy is,

                                    P.E = mgh

                                     K.E = 0

At height 'h/4', the total energy is

                                     P.E + K.E = mgh

                                     P.E = mgh/4

                                     K.E = 1/2 mv²

Therefore,

                                   mgh/4 + 1/2 mv² = mgh

                                    gh/4 + v²/2 = gh

Hence,

                                      v² = 3gh/2

Substituting in the K.E equation

                               K.E = 1/2 mv²

                                      = 1/2 m (3gh/2)

                                       = 3/4 mgh

                                        = 3/4 x 40000

                                         = 30000 J

Hence, the K.E of the roller coaster car is, K.E = 30000 J

You might be interested in
how could you prove to a skeptic that the beats are an interference effect that requires both sound sources? test out your metho
podryga [215]

Beats are interference patterns between two tones of different frequencies. To prove the skeptic first, play the recorded audio as there are no beats in it. Now take two sound sources with different frequencies. When both sources are turned on, we hear notes that rise and fall at equal intervals. That's what's called beats.

A frequency beat occurs when two waves with different frequencies overlap, causing alternating cycles of constructive and destructive interference between the waves.

When we tap the table with our finger, then put our ear to the table, and tap the table surface as far as 30 cm from our ear. Then the sound of beats on the table will sound louder when we put our ears on the table. So, it can be concluded that solid objects can conduct sound better than air. This is because the molecules or particles of solid objects are denser than air.

Learn more about the beat's frequency at brainly.com/question/14157895

#SPJ4

7 0
10 months ago
Does aluminum foil refract light? Why?
nikitadnepr [17]

yes it does it because the material cause it to refract and the stronger it is the more it will refract

4 0
3 years ago
Jennifer, who has a mass of 50.0 kg, is riding at 35.0 m/s in her red sports car when she must suddenly slam on the brakes to av
Assoli18 [71]

Answer:

Average force = 3.5 kN

Explanation:

Given:

Mass of Jennifer (m) = 50 kg

Initial velocity = 35 m/s

Time taken to stop body = 0.5 s

Find:

Average force

Computation:

v = u + at

0 = 35 + a(0.5)

Acceleration (a) =  - 70 m/s² = 70 m/s²

Average force = ma

Average force = (50(70)

Average force = 3500 N

Average force = 3.5 kN

6 0
3 years ago
A resistor is connected to a 36v power supply. An ammeter measures a current of 2.0 A going through it. Determine the resistance
m_a_m_a [10]

R = 18 ohms

Explanation:

Given:

V = 36 volts

I = 2.0 A

R = ?

Use Ohm's law to solve for the resistance:

V = IR

or

R = V/I

= (36 volts)/(2.0 A)

= 18 ohms

8 0
2 years ago
When we look at a star
stiv31 [10]

I'm not really sure what specific answer they're looking for, but if it's an open-ended question, then let's think about it this way...

A light year, is the distance it takes for light to travel in a year. If an object is 50,000 light years away, then by the time the light travels to us, 50,000 years has passed. We are looking at a 50,000 year old image of that object. (ignoring gravity and spatial expansion fun stuffs)

4 0
3 years ago
Other questions:
  • A basketball goal has a metal pole that is 3.50 m high at 21°C. On a cool day, at -11.5°C, it contracts by 0.00174 m.?
    11·2 answers
  • Does anybody watch this anime?
    11·2 answers
  • In an adiabatic process oxygen gas in a container is compressed along a path that can be described by the following pressure p,
    9·1 answer
  • Is Li Chen abiotic or biotic?
    5·2 answers
  • A 2 microcoulomb charge is placed at a distance of 0.25 m away from a 3.6 microcoulomb charge. Describe the type of electrostati
    15·2 answers
  • In certain cases, using both the momentum principle and energy principle to analyze a system is useful, as they each can reveal
    5·1 answer
  • Convert 68852 millijoules into Calories. (Write your answer in the decimal form. Do not include units in your answer).
    15·1 answer
  • HELPPPP WILL MARK B IF CORRECT!!!!
    9·2 answers
  • Juan amd kym have four samples of matter. They are observing and describing the properties of these samples. Which property will
    5·1 answer
  • Diffraction of light is the __________ of light as it passes through the Edges of a barrier or a slit.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!