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4 years ago

Which compares the thermal energy found in a piece of coal with the thermal energy found in a newly opened coal mine?

1 answer:

4 0

<span>The thermal energy found in a piece of coal is lesser than in the thermal energy in a newly opened coal mine. The newly opened coal mine requires a greater thermal energy to really open it due to its solid structure. Whereas in a piece of coal, it only requires a lesser amount of thermal energy to extract it.</span>

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A 2,300-kg truck is traveling down a highway at 32 m/s. What is the kinetic energy of the truck?

kondor19780726 [428]

m = mass of the truck = 23 00 kg

v = speed of the truck down the highway = 32 m/s

K = kinetic energy of the truck = ?

kinetic energy of the truck down the highway is given as

K = (0.5) m v²

inserting the values

K = (0.5) (2300) (32)²

K = (0.5) (2300) (1024)

K = (1150) (1024)

K = 1177600 J

hence the kinetic energy of the truck comes out to be 1177600 J

6 0

3 years ago

A model train engine was moving at a constant speed on a straight horizontal track. As the engine moved along, a marble was fir

bagirrra123 [75]

Answer:

The marble was moving in a projectile and the speed of the engine was 2.716 m/s

Explanation:

The vertical component of the marble's flight path relative to the train

is given by the equation y(t) = v*t - (4.9)*t^2,

where, v is the initial upward velocity of the marble relative to the train.

So with y(1) = v - 4.9 = 0 we have

v = 4.9 m/s.

The marble will reach maximum height after 0.5 seconds, at which the

height will be y(0.5) = (4.9)*(0.5) - (4.9)*(0.5)^2 = (4.9)*(0.25) = 1.225 m.

Now, the marble has a vertical velocity component of 4.9 m/s and a horizontal velocity component

of V m/s such that tan(61) = 4.9 / V

V = 4.9 / tan(61) = 2.716 m/s

This horizontal velocity component of the marble is the same as the

speed of the train i.e. 2.716 m/s.

3 0

3 years ago

"An object weighing 10.01 grams is placed in a graduated cylinder containing 3.90 mL of water. If the total volume of the object

Alex73 [517]

Answer:

Density of the object = 1.9399g/mL

Explanation:

Mass of object = 10.01g

Volume of water = 3.90mL

Volume of Object + Water = 9.06mL

Therefore, volume of Object = Volume of Object + Water - Volume of Water

= 9.06mL - 3.90mL

= 5.16mL

Density by definition is the mass per unit volume of a substance.

Density of the object = mass/volume

= 10.01/5.16

= 1.9399g/mL or 1.94kg/m3

8 0

3 years ago

A damped harmonic oscillator consists of a mass on a spring, with a small damping force that is proportional to the speed of the

exis [7]

Answer:

2.19 N/m

Explanation:

A damped harmonic oscillator is formed by a mass in the spring, and it does a harmonic simple movement. The period of it is the time that it does one cycle, and it can be calculated by:

T = 2π√(m/K)

Where T is the period, m is the mass (in kg), and K is the damping constant. So:

2.4 = 2π√(0.320/K)

√(0.320/K) = 2.4/2π

√(0.320/K) = 0.38197

(√(0.320/K))² = (0.38197)²

0.320/K = 0.1459

K = 2.19 N/m

4 0

3 years ago

Two blocks are placed at the ends of a horizontal massless board, as in the drawing. The board is kept from rotating and rests o

Andrew [12]

Answer:

The magnitude of the angular acceleration ∝ = $\frac{rxF}{2.8[tex]r^{2}$ }[/tex]

Explanation:

The angular acceleration ∝ is equal to the torque (radius multiplied by force) divided by the mass times the square of the radius. The magnitude of angular acceleration ∝ will have the equation above but we have to replace the mass in the equation by 2.8kg as stated.

7 0

3 years ago