A car is strapped to a rocket (combined mass = 661 kg), and its kinetic energy is 66,120 J. At this time, the rocket runs out of

Question

A car is strapped to a rocket (combined mass = 661 kg), and its kinetic energy is 66,120 J.

At this time, the rocket runs out of fuel and turns off, and the car deploys a parachute to slow down, and the parachute performs 36,733 J of work on the car.

What is the final speed of the car after this work is performed?

in progress 0
Tryphena 4 years 2021-08-07T19:27:05+00:00 1 Answers 6 views 0

Answers ( )

  1. haidang
    0
    2021-08-07T19:29:04+00:00
    Reply

    Answer:

    9.4 m/s

    Explanation:

    According to the work-energy theorem, the work done on the car is equal to its variation in kinetic energy, so:

    W=K_f - K_i

    where in this problem:

    W = -36,733 J is the work done on the car (negative because the car is slowing down)

    K_f is the final kinetic energy of the car

    K_i=66,120 J is its initial kinetic energy

    Solving for Kf,

    K_f = K_i + W = 66,120 +(-36,733)=29,387 J

    Now we can find the final speed of the car by writing the formula for the kinetic energy:

    K=\frac{1}{2}mv^2

    where:

    m = 661 kg is the mass of the car

    v is the final speed

    K = 29,387 J is the kinetic energy

    Solving for v,

    v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(29,387)}{661}}=9.4 m/s

Leave an answer

Browse

Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )