प्रकाशको आवर्तनको परिभाषा लेख्नुहोस् । कन्भेक्स ऐनाको अगाडि तपाई उभियौ भने तपाईको कस्तो आकृति बन्छ, लेख्नर

There is a skier at the top of a ski slope. The skier has potential energy. What gives the skier his potential energy? A. his sp

NeTakaya

Answer:C

Explanation:

Skier at the top of a ski has Potential Energy due to gravity.

Potential Energy is the Energy Possessed by an object when it attains a height concerning some zero level Position.

During the process of attaining the height, some work has to be done against gravity and this energy stored within the object after attaining some height w.r.t relative zero position.

7 0

3 years ago

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Two iron blocks are the same size. One block has a higher temperature than the other. Which describes the thermal energy of thes

a_sh-v [17]

Higher temperature means greater kinetic energy, which means the warmer block has greater thermal energy.

hoped this helped

7 0

3 years ago

In most circumstances, the normal force acting on an objectand

Lynna [10]

Answer:

Normal Force is usually perpendicular to the movement and static friction usually means that there is no movement.

Explanation:

The work donde by any force on an object is equal to the displacement of the object multiplied by the component of the force that is in the direction of the displacement.

Normal force is usually perpendicular to the movement, so there is no component in the direction of the displacement. This is why it is zero in most circumstances.

Static friction on the other hand, usually means that there is no movement at all (it's static). It means that there is no displacement between the object and ground (in most cases). If there is no displacement, there is no work.

4 0

3 years ago

A car at the top of a ramp starts from rest and rolls to the bottom of the ramp, achieving a certain final speed. If you instead

zimovet [89]

Answer:

It must be 4 times high.

Explanation:

Assuming that the car can be treated as a point mass, and that the ramp is frictionless, the total mechanical energy must be conserved.
This means, that at any time, the following must be true:
ΔK (change in kinetic energy) = ΔU (change in gravitational potential energy)

⇒ $m*g*h = \frac{1}{2} * m*v^{2}$

Let's call v₁, to the final speed of the car, and h₁ to the height of the ramp.

So, at the bottom of the ramp, all the gravitational potential energy

must be equal to the kinetic energy of the car (Defining the bottom of

the ramp as our zero reference for the gravitational potential energy):

$m*g*h_{1} = \frac{1}{2} * m*v_{1} ^{2}$ (1)

Now, let's do v₂ = 2* v₁
Replacing in (1) we get:

$m*g*h_{2} = \frac{1}{2} * m*(2*v_{1}) ^{2}$ (2)

Dividing (2) by (1), and rearranging terms, we get:
h₂ = 4* h₁

8 0

3 years ago

An average sleeping person metabolizes at a rate of about 80 W by digesting food or burning fat. Typically, 20% of this energy g

Leto [7]

Answer:

-4.7 x 10^-3 J/K-s

Explanation:

The Power generated by metabolizing food = 80 W

The watt W is equivalent to the Joules per sec J/s

therefor power = 80 J/s

20% of this energy is not used for heating, amount available for heating is

==> H = 80% of 80 = 0.8 x 80 = 64 J/s

The inner body temperature = 37 °C = 273 + 37 = 310 K

The entropy of this inner body ΔS = ΔH/T

ΔS = 64/310 = 0.2065 J/K-s

The skin temperature is cooler than the inner body by 7 °C

Temperature of the skin = 37 - 7 = 30 °C = 273 + 30 = 303 K

The entropy of the skin = ΔS = ΔH/T

ΔS = 64/303 = 0.2112 J/K-s

change in entropy of the person's body = (entropy of hot region: inner body) - (entropy of cooler region: skin)

==> 0.2065 - 0.2112 = -4.7 x 10^-3 J/K-s

8 0

3 years ago