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Anarel [89]
3 years ago
12

You push a 45 kg wooden box across a wooden floor at a constant speed of 1.0 m/s. The coefficient of kinetic friction is 0.25. N

ow you double the force on the box. How long would it take for the velocity of the crate to double to 2.0 m/s
Physics
1 answer:
tigry1 [53]3 years ago
8 0

Answer:

       t = 0.408 s

Explanation:

In this exercise we will use Newton's second law to find the acceleration and the kinematic relationships to find the time.

We use Newton's second law, for the first condition where the acceleration is zero

X axis

           F - fr = 0

Y Axis  

          N- W = 0

The expression for friction force is

        fr = μ N

       fr = μ mg

We substitute

      F = μ m g

This is the value for the applied force, now we apply the second condition, in this case the system has an acceleration

X axis

          2F- fr = ma

         a = (2F -fr) / m

Axis y

         N -W = 0

The friction force has the expression

        fr = μ N

        fr = μ W

We substitute

       a = (2F - μ m g) / m

       a = (2 μ mg - μ mg) / m

       a = μ g (2-1) = μ g

We calculate

      a = 0.25  9.8   1

      a = 2.45 m / s²

With this acceleration value we use the kinematics ratio to find the time

       v = v₀ + a t

The initial speed is 1 m / s and the final speed is 2 m / s

       t = (v-v₀) / a

       t = (2-1) / 2.45

       t = 0.408 s

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This means that 2.36 kJ of useful energy will be utilized per second. Converting this to the useful energy in hour gives us:

Average energy in one hour = 2.36 kJ/s * 3600 s/h = 8496 kJ

The specific heat capacity of water is 4.18 kJ/kg.C which means it will take 4.18 kJ of energy to raise the temperature of 1 kg of water by 1 degree C. Equating the energy change of the water for the given temperature rise and mass (unknown) to the useful energy utilized in one hour, we can solve to determine the unknown mass. This will give us the mass of water heated in one hour:

Energy = mass * specific heat capacity * (final temperature - initial temperature)

8496 = mass * 4.18 * (60 - 16)

mass = 46.19 kg

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volume = 46.19 L

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What does an electromaget do
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Will a beam of light that is, at first, in air and oriented perpendicular to the surface of a body of water be deflected as a re
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When a beam of light  that is, at first, in air and oriented perpendicular to the surface of a body of water be deflected as a result of transition into water--------It does not deflect , the light direction will not change.

What happens to light when it passes through air?

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4 0
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Explain what each quantum number in a quantum number set tells you about the electron. Compare and contrast the locations and pr
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Answer:

The change in length per unit length per degree rise in temperature of copper is 0.000017k

Explanation:

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Therefore, the change in length per unit length per degree rise in temperature (k) is 0.000017

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