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3 years ago

A motor produces less mechanical energy than the energy it uses because the motor?

1 answer:

3 0

A motor produces less mechanical energy than the energy it uses because the motor looses some energy to heat.

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In an experiment, a disk is set into motion such that it rotates with a constant angular speed. As the disk spins, a small spher

boyakko [2]

Answer:

L₀ = L_f , K_f < K₀

Explanation:

For this exercise we start as the angular momentum, with the friction force they are negligible and if we define the system as formed by the disk and the clay sphere, the forces during the collision are internal and therefore the angular momentum is conserved.

This means that the angular momentum before and after the collision changes.

Initial instant. Before the crash

L₀ = I₀ w₀

Final moment. Right after the crash

L_f = (I₀ + mr²) w

we treat the clay sphere as a point particle

how the angular momentum is conserved

L₀ = L_f

I₀ w₀ = (I₀ + mr²) w

w = $\frac{I_o}{I_o + m r^2}$ w₀

having the angular velocities we can calculate the kinetic energy

starting point. Before the crash

K₀ = ½ I₀ w₀²

final point. After the crash

K_f = ½ (I₀ + mr²) w²

sustitute

K_f = ½ (I₀ + mr²) ( $\frac{I_o}{I_o + m r^2}$ w₀)²

Kf = ½ $\frac{I_o^2}{ I_o + m r^2}$ w₀²

we look for the relationship between the kinetic energy

$\frac{K_f}{K_o}$ = $\frac{I_o}{I_o + m r^2}$

$\frac{K_f}{K_o } < 1$

K_f < K₀

we see that the kinetic energy is not constant in the process, this implies that part of the energy is transformed into potential energy during the collision

6 0

3 years ago

Which object would have MORE kinetic energy?

valentinak56 [21]

Answer:

A dump truck going 70 mph

Explanation:

hope it helps you

6 0

3 years ago

Read 2 more answers

Energy Transformation

Serjik [45]

Answer:

K =400000 J

Explanation:

Kinetic Energy

Is the energy an object has due to its state of motion. It's proportional to the square of the speed.

The equation for the kinetic energy is:

$\displaystyle K=\frac{1}{2}mv^2$

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

The car has a mass of m=2000 Kg and travels at v=20 m/s. Calculating the kinetic energy:

$\displaystyle K=\frac{1}{2}2000*20^2$

Calculating:

K =400000 J

3 0

3 years ago

At room temperature ice will melt while a brass lamp will stay as a solid. This must mean that the melting point of water is ___

UkoKoshka [18]

If solid, cold metal like brass doesn't melt at room temperature like ice does, than the bass can stand much more heat then a ice cube, so it needs to be hotter to melt, so the melting point of ice is lower then brass's melting point

4 0

3 years ago

Read 2 more answers

What type of motion is shown with this graph? (5 points)

Vladimir [108]

It should be Constant speed. The line goes straight & doesn’t change within the graph.

7 0

3 years ago