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kykrilka [37]
3 years ago
7

Which would be the best example to demonstrate the principle of conservation of energy? A) a stone is crushed B) light bends aro

und a sharp edge C) a pendulum swings back and forth D) a balloon inflates when air is blown into it
Physics
2 answers:
Gnom [1K]3 years ago
7 0

The correct answer to the question is : C) A pendulum swings back and forth.

EXPLANATION:

Before answering this question, first we have to understand the law of conservation of energy.

As per law of conservation of energy, energy can neither be created not be destroyed. It can only change from one form to another form, and the total energy of the universe is always constant.

As per the question, we have a pendulum which is moving back and forth.

Let us consider a pendulum which is taken to some height from its equilibrium or mean point. The energy possessed by the pendulum at this height is gravitational potential energy. When the pendulum is released, the potential energy is converted into kinetic energy. At mean point, whole of its potential energy is converted into kinetic energy.

Due to inertia, the pendulum reaches at the other extreme point. During its movement from mean point to extreme point, the kinetic energy is converted into potential energy. At extreme point, whole of its kinetic energy must have converted into potential energy. The same process will be repeated.

Hence, it obeys law of conservation of energy.

Hence, swinging of pendulum back and forth is the best example to demonstrate the law of conservation of energy.

Daniel [21]3 years ago
6 0
The answer is a pendulum swings back an forth.
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The movement of both oxygen and carbon dioxide in the body is accomplished by ___.
ad-work [718]

Answer: Diffusion

Explanation: Please give brainliest

7 0
3 years ago
A 59 kg man has a total mechanical energy of 150,023. J. If he is swinging downward and is currently 2.6 m above the ground, wha
Alborosie

Answer:

v = 70.95 \ m/s.

Explanation:

Given data:

Mass of the man, m = 59 \ kg

Total mechanical energy, E_{i} = 150,023 \ \rm J

Height, h = 2.6 \ m

Suppose there is no external force acting on the man. In this situation, the total mechanical energy (kinetic + potential) will remain steady.

Let the speed of the man at 2.6 m be <em>v</em>.

Thus,

E_{i} = E_{f}

E_{i} = \frac{1}{2}mv^{2} + mgh

150023 = 0.5 \times 59 \times v^{2} + 59 \times 9.80 \times 2.6

\Rightarrow \ v = 70.95 \ m/s.

6 0
3 years ago
A ray of light is incident on an air/water interface.
elixir [45]

Answer:

\theta_2=sin^{-1}(\dfrac{n_1\ sin\theta_1}{n_2})

Explanation:

Given that,

The ray makes an angle of 32 degrees with respect to the normal of the surface.

The refractive index of air, n_1=1

The refractive index of water, n_2=1.33

Snell's law is given by :

n_1\ sin\theta_1=n_2\ sin\theta_2

sin\theta_2=\dfrac{n_1\ sin\theta_1}{n_2}

\theta_2=sin^{-1}(\dfrac{n_1\ sin\theta_1}{n_2})

So, option (4) is correct. Hence, this is the required solution.    

3 0
3 years ago
. In a high school graduating class of 100 students, 47 studied mathematics, 61 studied physics, and 25 studied both mathematics
gtnhenbr [62]

Answer:

given,

Probability of student studying math P(M)=\dfrac{45}{100} = 0.45

Probability of student studying physicsP(P) = \dfrac{61}{100} = 0.61

Probability of student studying both math and physics together P(M∩P) = \dfrac{25}{100} = 0.25

a) student took mathematics or physics

P(M∪P) = P(M) + P(P) - P(M∩P)

             = 0.45 + 0.61  - 0.25

             = 0.81

b) student did not take either of the subject

P((M∪P)') = 1 - 0.81

               = 0.19

c) Student take physics but not mathematics

P(P∩M') = P(P) - P(P∩M)

             = 0.61 - 0.25

             = 0.36

studying physics and mathematics is  not mutually exclusive because we can study both the subjects.

8 0
3 years ago
A uniform rod is attached to a wall by a hinge at its base. The rod has a mass of 6.5 kg, a length of 1.3 m, is at an angle of 1
liubo4ka [24]

Answer:

tension wire 104 N, horizontal force hinge 104 N, vertical force hinge 63.7 N

Explanation:

The system described is in static equilibrium under the action of several forces, which are shown in the attached diagram, where T is the tension of the wire, W is the weight of the bar, Fx is the horizontal reaction of the wall and Fy It is the vertical reaction of the wall.

The directions of the forces are indicated by the arrows and are marked intuitively, but when solving the problem if one gives a negative value this indicates that the direction is wrong, but does not alter the results of the problem

For the resolution we use Newton's second law, both in translational and rotational equilibrium, if necessary.

We must establish a reference system to assign the positive meaning, we place it with the origin in the hinge, and the positive directions to the right and up. The location of the coordinate system allows us to eliminate the reaction of the hinge by having zero distance to origin. We write the equilibrium equations for each axis

     ∑ Fx = 0

     Fx -T =0

     ∑ Fy =0

     Fy -W =O      W = m g

     ∑τ =0

      -T dy + W dx =0

For rotational equilibrium we take the positive direction as counterclockwise rotation and distance is the perpendicular distance of the force to the axis of the coordinate system

     

       dy = L sin 17

      dx = (L/2) cos 17

Where L is the length of the bar and the weight is applied at the center of it, we write and simplify the equation

    -T L sin 17 + mg (L / 2) cos 17 = 0

   - T sin 17 + mg/2  Cos 17 =0

We write the three equations together

     Fx- T = 0

     Fy -W = 0

     -T sin 17 + (m g / 2) cos 17 = 0

a) With the third equation we can find the wire tension

     T = m g / 2 cos 17 / sin17

     T = 6.5  9.8/2 cotan 17

     T = 104 N

b) We use the first equation to find Fx

       Fx- T =0

       Fx = T = 104 N

c) We use the second equation to find Fy

 

       Fy = W = m g

       Fy = 6.5 9.8

       Fy = 63.7 N

4 0
3 years ago
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