Ask Question
12 May, 15:53

An object is thrown straight up with an initial velocity of 10 m/s, and there is an air resistance force causing an acceleration of 3 m/s2 opposite the direction of motion. With what speed does the object return to the ground?

+2
Answers (1)
  1. 12 May, 16:04
    0
    Vf = 7.29 m/s

    Explanation:

    Two force act on the object:

    1) Gravity

    2) Air resistance

    Upward motion:

    Initial velocity = Vi = 10 m/s

    Final velocity = Vf = 0 m/s

    Gravity acting downward = g = - 9.8 m/s²

    Air resistance acting downward = a₁ = - 3 m/s²

    Net acceleration = a = - (g + a₁) = - (9.8 + 3) = - 12.8 m/s²

    (Acceleration is consider negative if it is in opposite direction of velocity)

    Now

    2as = Vf² - Vi²

    ⇒ 2 * (-12.8) * s = 0 - 10²

    ⇒-25.6 * s = - 100

    ⇒ s = 100 / 25.6

    ⇒ s = 3.9 m

    Downward motion:

    Vi = 0 m/s

    s = 3.9 m

    Gravity acting downward = g = 9.8 m/s²

    Air resistance acting upward = a₁ = - 3 m/s²

    Net acceleration = a = g - a₁ = 9.8 - 3 = 6.8 m/s²

    Now

    2as = Vf² - Vi²

    ⇒ 2 * 6.8 * 3.9 = Vf² - 0

    ⇒ Vf² = 53. 125

    ⇒ Vf = 7.29 m/s
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “An object is thrown straight up with an initial velocity of 10 m/s, and there is an air resistance force causing an acceleration of 3 m/s2 ...” in 📘 Physics if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers