answer.
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
bogdanovich [222]
2 years ago
12

A 0.75 kg wood block is pushed 0.2 m into a horizontal spring with a spring constant of 50 N/m and released. a. How much spring

potential energy is in the system before the wood block begins to move? b. If the surface is frictionless, what is the kinetic energy of the block as it leaves the spring? c. If the surface is frictionless, what is the velocity of the block as it leaves the spring? d. Assuming the surface is not frictionless, and the wood block leaves the spring at a velocity of 1.32 m/s. How much energy is lost due to friction?
Physics
1 answer:
DochEvi [55]2 years ago
3 0

A) Elastic potential energy: 1 J

B) Kinetic energy: 1 J

C) Velocity of the block: 1.63 m/s

D) Energy lost due to friction: 0.35 J

Explanation:

A)

The elastic potential energy of a spring is given by the equation

E=\frac{1}{2}kx^2

where

k is the spring constant

x is the compression of the spring

In this problem, we have:

k = 50 N/m is the spring constant

x = 0.2 m is the compression of the spring

Therefore, the elastic potential energy is

E=\frac{1}{2}(50)(0.2)^2=1 J

B)

In this case, the surface is frictionless.

This means that there is no friction force acting on the wood block. Therefore, this also means that the total mechanical energy of the system, which is the sum of kinetic and potential energy, is constant:

E=PE+KE

where

PE is the elastic potential energy

KE is the kinetic energy

When the spring is released, the spring returns to its original length, therefore x = 0; so, all the initial potential energy is converted into kinetic energy, therefore the kinetic energy of the block is

KE = 1 J

c)

The kinetic energy of an object is the energy possessed by the object due to its motion, and it is given by

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

where

m is the mass of the object

v is its velocity

For the block in this problem,

m = 0.75 kg

Therefore, since the kinetic energy is

KE = 1 J

The velocity of the block is

v=\sqrt{\frac{2E}{m}}=\sqrt{\frac{2(1)}{0.75}}=1.63 m/s

D)

If the block leaves the spring with a velocity of

v = 1.32 m/s

Then it means that its kinetic energy is

KE'=\frac{1}{2}mv^2=\frac{1}{2}(0.75)(1.32)^2=0.65 J

This also means that the total mechanical energy of the system as the block is released is

E' = 0.65 J

We said instead that the total mechanical energy when the spring was compressed was

E = 1 J

Therefore, the energy lost due to friction is

\Delta E=E-E'=1-0.65=0.35 J

Learn more about kinetic and potential energy:

brainly.com/question/6536722

brainly.com/question/1198647

brainly.com/question/10770261

#LearnwithBrainly

You might be interested in
Anthony and Maelynn are watching a football game outside on a sunny day. Anthony is wearing a black shirt and Maelynn is wearing
melomori [17]

Answer: Anthony will be warmer after the game.

Explanation :

Anthony and Maelynn are watching a football game outside on a sunny day. Anthony is wearing a black shirt and Maelynn is wearing a white shirt. Anthony will be warmer after the game. The black color is a good absorber of radiation and a bad reflector.

The black color absorbs heat until a thermal equilibrium is attained. So, it is advisable to wear cotton clothes in summers not dark colored clothes.

7 0
2 years ago
Read 2 more answers
Using energy considerations and assuming negligible air resistance, show that a rock thrown from a bridge 20.0 m above water wit
melamori03 [73]

Answer:

Explanation:

Given that,

Height of the bridge is 20m

Initial before he throws the rock

The height is hi = 20 m

Then, final height hitting the water

hf = 0 m

Initial speed the rock is throw

Vi = 15m/s

The final speed at which the rock hits the water

Vf = 24.8 m/s

Using conservation of energy given by the question hint

Ki + Ui = Kf + Uf

Where

Ki is initial kinetic energy

Ui is initial potential energy

Kf is final kinetic energy

Uf is final potential energy

Then,

Ki + Ui = Kf + Uf

Where

Ei = Ki + Ui

Where Ei is initial energy

Ei = ½mVi² + m•g•hi

Ei = ½m × 15² + m × 9.8 × 20

Ei = 112.5m + 196m

Ei = 308.5m J

Now,

Ef = Kf + Uf

Ef = ½mVf² + m•g•hf

Ef = ½m × 24.8² + m × 9.8 × 0

Ef = 307.52m + 0

Ef = 307.52m J

Since Ef ≈ Ei, then the rock thrown from the tip of a bridge is independent of the direction of throw

7 0
2 years ago
In a house the temperature at the surface of a window is 28.9 °C. The temperature outside at the window surface is 7.89 °C. Heat
Alenkasestr [34]

Answer:

-13.18°C

Explanation:

To develop the problem it is necessary to consider the concepts related to the thermal conduction rate.

Its definition is given by the function

\frac{Q}{t} = \frac{kA\Delta T}{d}

Where,

Q = The amount of heat transferred

t = time

k = Thermal conductivity constant

A = Cross-sectional area

\Delta T = The difference in temperature between one side of the material and the other

d= thickness of the material

The problem says that there is a loss of heat twice that of the initial state, that is

Q_2 = 2*Q_1

Replacing,

kA\frac{\Delta T_m}{x} = 2*kA\frac{\Delta T}{x}

\frac{\Delta T}{x}=2*\frac{\Delta T}{x}

\frac{T_i-T_o}{x} = 2\frac{T_1-T_2}{x}

\frac{28.9-T_o}{x} = 2\frac{28.9-7.86}{x}

Solvinf for T_o,

T_o = -13.18

Therefore the temprature at the outside windows furface when the heat lost per second doubles is  -13.18°C

3 0
2 years ago
How does the sun transfer energy to Earth?
aleksley [76]

Answer:

By electromagnetic waves.

Explanation:

The sun transfers heat to earth via electromagnetic waves  in twomajor  ways:

Radiation- this is the transfer of energy by invisible electromagnetic ways.

Convection-The radiant sun energy warms the atmosphere and becomes heat energy. This transfer of heat through movement of fluids or usually air is called convection.

4 0
2 years ago
Read 2 more answers
An object at rest is suddenly broken apart into two fragments by an explosion one fragment acquires twice the kinetic energy of
satela [25.4K]
<span>First, we use the kinetic energy equation to create a formula: Ka = 2Kb 1/2(ma*Va^2) = 2(1/2(mb*Vb^2)) The 1/2 of the right gets cancelled by the 2 left of the bracket so: 1/2(ma*Va^2) = mb*Vb^2 (1) By the definiton of momentum we can say: ma*Va = mb*Vb And with some algebra: Vb = (ma*Va)/mb (2) Substituting (2) into (1), we have: 1/2(ma*Va^2) = mb*((ma*Va)/mb)^2 Then: 1/2(ma*Va^2) = mb*(ma^2*Va^2)/mb^2 We cancel the Va^2 in both sides and cancel the mb at the numerator, leving the denominator of the right side with exponent 1: 1/2(ma) = (ma^2)/mb Cancel the ma of the left, leaving the right one with exponent 1: 1/2 = ma/mb And finally we have that: mb/2 = ma mb = 2ma</span>
8 0
2 years ago
Other questions:
  • A certain liquid has a density of 2.67 g/cm3. 1340 g of this liquid would occupy a volume of ________ l.
    8·2 answers
  • A steady circular __________ light means drivers must stop at a marked stop line.
    7·2 answers
  • At a given instant of time, a car and a truck are traveling side by side in adjacent lanes of a highway. The car has a greater v
    8·1 answer
  • 2. The water is then heated to its boiling point. Calculate the specific latent heat of
    9·1 answer
  • The gravitational force produce between any two object kept 2.5×10 to the power 4 km apart is 580N.At what distance should they
    15·1 answer
  • A boy of mass 80 kg slides down a vertical pole, and a frictional force of 480 N acts on him. What is his acceleration as he sli
    5·1 answer
  • Boat A and Boat B have the same mass. Boat A's velocity is three times greater than that of Boat B. Compared to
    7·1 answer
  • A constant-velocity horizontal water jet from a stationary nozzle impinges normally on a vertical flat plate that rides on a nea
    10·1 answer
  • A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able to slide pa
    6·1 answer
  • A rock climber’s shoe loosens a rock, and her climbing buddy at the bottom of the cliff notices that the rock takes 3.20 s to fa
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!