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2 years ago

I need help please, thank you!!!

Physics

1 answer:

stiks02 [169]2 years ago

4 0

Answer:

135 mph

because 7+9=16

8 is left

if 7=40

9=50

then 8=45

add 40+50+45mph

=135

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Ice has a specific heat of 2090 J/(kg C) and water has a specific heat of 4186 J/(kg C). Water has a latent heat of fusion of 3.

zepelin [54]

Answer:

3.1 × 10⁷ J

Explanation:

The total heat required is the sum of the heats required in each stage.

1) Solid: from -60°C to 0°C.

Q₁ = c(s) × m × ΔT = (2090 J/kg.°C) × 10 kg × (0°C - (-60°C)) = 1.3 × 10⁶ J

where,

c(s): specific heat of the solid

m: mass

ΔT: change in the temperature

2) Solid to liquid at 0°C

Q₂ = Qf × m = (3.3 × 10⁵ J/kg) × 10 kg = 3.3 × 10⁶ J

where,

Qf: latent heat of fusion

3) Liquid: from 0°C to 100°C

Q₃ = c(l) × m × ΔT = (4186J/kg.°C) × 10 kg × (100°C - 0°C) = 4.2 × 10⁶ J

where,

c(l): specific heat of the liquid

4) Liquid to gas at 100 °C

Q₄ = Qv × m = (2.26 × 10⁶ J/kg) × 10 kg = 2.26 × 10⁷ J

where,

Qv: latent heat of vaporization

Total heat

Q₁ + Q₂ + Q₃ + Q₄

1.3 × 10⁶ J + 3.3 × 10⁶ J + 4.2 × 10⁶ J + 2.26 × 10⁷ J = 3.1 × 10⁷ J

3 0

2 years ago

Heat engines use heat to do work. true or false.

ankoles [38]

True.

Heat engines makes use of heat to do work.

4 0

2 years ago

Read 2 more answers

A glass dropped on the floor is more likely to break if the floor is concrete

garik1379 [7]

False , (No) because if its a regular floor it will more likely break because of the flat surface but if it is concrete then it has more of a chance because it has edges and dents which will help prevent it from breaking.

4 0

2 years ago

One speed skater starts across a frozen lake at an average speed of 8 m/s. Ten seconds later, a second speed skater starts from

Luba_88 [7]

Answer:

40 s

Explanation:

After 10 seconds, the first skater would have a 8m/s * 10s = 80 m head start

Let t be the number of seconds after the second skater starts will the second skater overtake the first skater

The distance traveled by the first skater after t seconds is

$s_1 = v_1t = 8t$

Similarly the distance traveled by the 2nd skater after t seconds is

$s_2 = v_2t = 10t$

Since the 2nd skater catches up to the 1st one after 80 m behind, the distance traveled by the 2nd one must be 80m greater than the distance of the 1st skater

$s_2 = s_1 + 80$

We can substitute $s_1 = 8t, s_2 = 10t$

$10t = 8t + 80$

$2t = 80$

$t = 80 / 2 = 40 s$

7 0

2 years ago

Rank these electromagnetic waves on the basisof their speed (in vacuum). Rank from fastest to slowest. To rank items as equivale

adelina 88 [10]

Answer: On the basis of speed they are all equivalent.

Yellow light = Fm radio wave = Green light = X-ray = AM radio wave = Infrared wave

Explanation:

Yellow light, Fm radio wave, Green light ,X-ray, AM radio wave and Infrared wave are all electromagnetic waves, and all electromagnetic waves move at the same vacuum speed which is the speed of light and is approximately 3.0x10^8 m/s.

They only differ in wavelength and frequency

c = λf

c (speed of light) = λ (wavelength) x f (frequency)

Therefore; on the basis of speed they are all equivalent.

Yellow light = Fm radio wave = Green light = X-ray = AM radio wave = Infrared wave

6 0

2 years ago