a brick of mass 0.8 kg is accidentally dropped from a high scaffolding. it reaches the ground with a kinetic energy of 240 J. How high is sc

Question

a brick of mass 0.8 kg is accidentally dropped from a high scaffolding. it reaches the ground with a kinetic energy of 240 J. How high is scaffolding ?(Take acceleration due to gravity g be 10 m s-¹)​

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Khải Quang 13 mins 2021-07-22T22:06:49+00:00 1 Answers 0 views 0

Answers ( )

    0
    2021-07-22T22:08:12+00:00

    Answer:

    30 m

    General Formulas and Concepts:

    Energy

    Gravitational Potential Energy: \displaystyle U_g = mgh

    • m is mass (in kg)
    • g is gravity
    • h is height (in m)

    Kinetic Energy: \displaystyle KE = \frac{1}{2}mv^2

    • m is mass (in kg)
    • v is velocity (in m/s²)

    Law of Conservation of Energy

    Explanation:

    Step 1: Define

    Identify variables

    [Given] m = 0.8 kg

    [Given] g = 10 m/s²

    [Given] U = 240 J

    [Solve] h

    Step 2: Solve for h

    1. [LCE] Substitute in variables [Gravitational Potential Energy]:                      (0.8 kg)(10 m/s²)h = 240 J
    2. Multiply:                                                                                                             (8 kg · m/s²)h = 240 J
    3. Isolate h [Cancel out units]:                                                                             h = 30 m

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