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
professor190 [17]
3 years ago
13

A 6.5 kg rock thrown down from a 120m high cliff with initial velocity 18 m/s down. Calculate

Physics
1 answer:
Olegator [25]3 years ago
5 0

Answer:

See the answers below.

Explanation:

In order to solve this problem we must use the principle of energy conservation. Which tells us that the energy of a body will always be the same regardless of where it is located. For this case we have two points, point A and point B. Point A is located at the top at 120 [m] and point B is in the middle of the cliff at 60 [m].

E_{A}=E_{B}

The important thing about this problem is to identify the types of energy at each point. Let's take the reference level of potential energy at a height of zero meters. That is, at this point the potential energy is zero.

So at point A we have potential energy and since a velocity of 18 [m/s] is printed, we additionally have kinetic energy.

E_{A}=E_{pot}+E_{kin}\\E_{A}=m*g*h+\frac{1}{2}*m*v^{2}

At Point B the rock is still moving downward, therefore we have kinetic energy and since it is 60 [m] with respect to the reference level we have potential energy.

E_{B}=m*g*h+\frac{1}{2}*m*v^{2}

Therefore we will have the following equation:

(6.5*9.81*120)+(0.5*6.5*18^{2} )=(6.5*9.81*60)+(0.5*6.5*v_{B}^{2} )\\3.25*v_{B}^{2} =4878.9\\v_{B}=\sqrt{1501.2}\\v_{B}=38.75[m/s]

The kinetic energy can be easily calculated by means of the kinetic energy equation.

KE_{B}=\frac{1}{2} *m*v_{B}^{2}\\KE_{B}=0.5*6.5*(38.75)^{2}\\KE_{B}=4878.9[J]

In order to calculate the velocity at the bottom of the cliff where the reference level of potential energy (potential energy equal to zero) is located, we must pose the same equation, with the exception that at the new point there is only kinetic energy.

E_{A}=E_{C}\\6.5*9.81*120+(0.5*9.81*18^{2} )=0.5*6.5*v_{C}^{2} \\v_{c}^{2} =\sqrt{2843.39}\\v_{c}=53.32[m/s]

You might be interested in
GIVING BRAINLY, FOLLOW, STARS AND POINTS
Nikitich [7]

Answer:

Wheres. The. Pics. Of. The. Structures

Explanation:

4 0
2 years ago
Name any two liquid which are found in our human eyes​
Romashka [77]

Aqueous humor and vitreous humor are the liquids present in the human eye.

<em>Hope </em><em>it</em><em> helped</em><em> you</em><em>.</em><em>.</em><em>.</em><em> </em><em>pls </em><em>mark</em><em> brainliest</em>

8 0
2 years ago
YO CAN ANYONE DO THE BLANK COLUMN AND THE QUESTION PART RQ PLS!!
VikaD [51]

Answer:

stryo:  1

wood: 1

ice: 1

brick: 2

aluminum: 2.7

Explanation:

d= mass/ total volume

(fyi: for aluminum, they did the subtraction wrong to find the total volume. it is actually 5 or 5.00)

6 0
3 years ago
A student who takes a multiple-choice test by reading the stem of each item, generating the correct response before looking at t
Ludmilka [50]

Answer:

(A) a heuristic

Explanation:

A heuristic:It is a reasoning strategy to find answers, make judgement about any something."

It is possible to choose between the options given, we have the following interpretation as; Interpretation: "A heuristic: finding answers is a thinking technique, evaluating something." Mechanism: In the heuristic approach the method is to find solutions or answers to a question by choosing the right and optimal compositions.

5 0
3 years ago
A police car chases a speeder along a straight road towards a cliff both vehicles move at 160km/h the siren on the police car pr
natta225 [31]

Answer:

f ’= 97.0 Hz

Explanation:

This is an exercise of the doppler effect use the frequency change due to the relative movement of the fort and the observer

in this case the source is the police cases that go to vs = 160 km / h

and the observer is vo = 120 km / h

the relationship of the doppler effect is

          f ’= f₀ (v + v₀ / v- v_{s})

let's reduce the magnitude to the SI system

            v_{s} = 160 km / h (1000 m / 1km) (1h / 3600s) = 44.44 m / s

            v₀ = 120 km / h (1000m / 1km) (1h / 3600s) = 33.33 m / s

we substitute in the equation of the Doppler effect

          f ‘= 100 (330+ 33.33 / 330-44.44)

          f ’= 97.0 Hz

4 0
3 years ago
Other questions:
  • Where are some of Earth's youngest rocks found?
    8·1 answer
  • ¿Cuál es el rango de frecuencias comprendido entre las longitudes de onda de 220 nm, 350 nm,
    14·1 answer
  • A stone is thrown vertically upwards with a speed of 30.0 m/s.
    5·1 answer
  • The maximum mass of a white dwarf is ______ times the mass of the sun.
    11·1 answer
  • The potential difference between two parallel plates is 227 V. If the plates are 6.8 mm apart, what is the electric field betwee
    9·1 answer
  • A rope is vibrating at high frequency. The length of the rope is 2.40 meters. A snapshot of the rope at a given moment in time
    9·1 answer
  • Which of these is the BEST answer for why science is important?
    6·1 answer
  • In an electrical circuit, what happens to the current flowing through the wire if the initial voltage of 18 V is doubled, and th
    11·2 answers
  • What is displacement and distance
    7·1 answer
  • Share your thoughts about this statement by John Wesley<br> "Electricty is the soul of universe"
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!