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
siniylev [52]
3 years ago
10

A boulder is raised above the ground, so that its potential energy relative to the ground is 200 J. Then it is dropped. Estimate

what its kinetic energy will be just before hitting the ground.
Physics
1 answer:
babymother [125]3 years ago
6 0

Answer:

200 J

Explanation:

In this problem, I assume there is no air resistance, so the  system is isolated (=no external forces).

For an isolated system, the total mechanical energy is constant, and it is given by:

E=KE+PE

where

KE is the kinetic energy

PE is the potential energy

The kinetic energy is the energy due to the motion of the object,  while the potential energy is the energy due to the position of the object relative to the ground.

At the beginning, when the boulder is raised above the ground, its height above the ground is maximum, while its  speed is zero; it means that all its mechanical energy is just potential energy, and it is:

E=PE_{max}=200 J

As the boulder falls  down, its altitude decreases, so its potential energy decreases, while the speed increases, and the kinetic energy increases. Therefore, potential energy is converted into kinetic energy.

Eventually, just before the boulder hits the ground, the height of the object is zero, and the speed is maximum; this means that all the energy has now converted into kinetic energy, and we have

E=KE_{max}=200 J

Therefore, the kinetic energy just before hitting the ground is 200 J.

You might be interested in
Thermal Conductors don't have to be hot to transfer heat, explain a situation when a ice cube would still transfer heat to anoth
barxatty [35]
An ice cube would transfer heat to another object whose temperature
is lower than zero°C (32°F).

A block of "dry ice" is sitting there at a temperature of -78°C (-109°F).
An ice cube helps to melt dry ice nice and fast.

If you could find a block of solid nitrogen, its temperature would be
63K (-210°C, -346°F).  An ice cube would transfer heat to that baby
so fast that it would instantly boil.

6 0
3 years ago
Doubling the frequency of a wave source doubles the speed of the wave assuing that wavelength remains the same? True or false? W
SVETLANKA909090 [29]

Answer:true,because velocity is directly proportional to speed or velocity

Explanation:

Velocity = frequency x wavelength

The velocity or speed varies directly with the frequency, so as the frequency is increased, the velocity or speed is also increased

8 0
3 years ago
In February 1955, a paratrooper fell 365 m from an airplane without being able to open his chute but happened to land in snow, s
DaniilM [7]

Answer:

a. i=4760 kg*m/s

b. D_U= 1.11 m

Explanation:

a)

F= 120,000N

Kinetic energy @ impact = 120,000*depth

K_E= (1/2)*85kg*(56m/s)^2

K_E=133280 J

D_U= \frac{133280J}{120000N} = 1.11 m

b)

The momentum is equal to the impulse on him from the snow so:

p=m*v

p=85kg*56m/s

i=4760 kg*m/s

7 0
3 years ago
If X And Y two vectors have same magnitude, if X^Y=2 and X.Y =4 so, the angle between them ?​
devlian [24]

Answer: If x + y = a, xxy = b and x • a = 1 , then 2 (a~ - l)a- a x b (b2 ... xy-plane, then the vector in the same plane having projections

7 0
2 years ago
Calculate the total resistance for a 650ohm , a 350 ohm , and a 1000 ohm resistor connected in series
Mekhanik [1.2K]

Answer:

2000 ohms

Explanation:

Resisters in series just add.

Rt = R1 + R2 + R3

R1 = 650 ohm

R2 = 350 ohm

R3 = 1000 ohm

Rt = 650 + 350 + 1000

Rt = 2000 ohms.

5 0
3 years ago
Read 2 more answers
Other questions:
  • Give a combination of four quantum numbers that could be assigned to an electron occupying a 5p orbital.
    13·1 answer
  • Which of these is the best exclamation for why to negatively charged balloons, if put close, will repel?
    14·1 answer
  • Sodium is a highly reactive metal and chlorodyne is a poisonous gas which compound do they for a chemically combines
    9·1 answer
  • Penny has two dogs: Fluffy (left) and Butch (right).
    11·2 answers
  • Where can classic examples of shield volcanoes be found?
    6·1 answer
  • Nearly all the light that strikes an opaque object will pass through and cast a shadow
    14·2 answers
  • Which wave would cause destructive interference at every point of the wavelength and completely cancel out the wave?
    7·2 answers
  • If a wire lies withina magnetic field what must be true for the magnetic field to produce an electric current in the wire
    7·1 answer
  • Hellp.....its physics
    12·2 answers
  • 7. A child of mass m starts from rest and slides without friction from a height h along a curved waterslide (Fig. P5.46). She is
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!