College physics

posted by .

A toy car has a mass of 120g, including two 1.5 V batteries connected in series. Suppose the motor that drives the car is 80\% efficient (i.e., 80\% of the electric energy goes to the drive wheels, 20\% is dissipated as heat) and that friction and air resistance are negligible. How much charge passes through the batteries during the time it takes the car to accelerate from rest to 1.5 m/s?

  • College physics -

    Change in kinetic energy of car = (1/2) m v^2
    divide that by 0.8
    The result is the energy taken from the battery, q V.
    V is 1.5*2 = 3 volts
    solve for q

  • College physics -

    0.036 Coulombs

  • College physics -

    real answer=0.05625 coulombs

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. AP Physics

    A 1050kg car has four 15kg wheels. When the car is moving, what fraction of the total kinetic energy of the car is due to the rotation of the wheels about their axles?
  2. Math

    Three men named Greene, Grey, and Tann along with two women name Browne and Whyte, each drive the car in their car pool on a different one of the five weekdays each week. Each person's car is a different one of these five colors: brown, …
  3. physics

    A car is designed to get its energy from a rotating flywheel with a radius of 1.50 m and a mass of 600 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 4000 rev/min. …
  4. Physics Rotaional Kinetic Energy

    A car is designed to get its energy from a rotating flywheel with a radius of 1.50 m and a mass of 600 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 4000 rev/min. …
  5. Physics

    A 1900 car starts from rest and drives around a flat 50--diameter circular track. The forward force provided by the car's drive wheels is a constant 1300 . A) What is the magnitude of the car's acceleration at ?
  6. physicsss ;o

    a 12 V car battery is found to be capable of storing 2.0 kW*h of eletrical energy. for a certain eletric car, it is necessary to develop 10 kW of power to drive at 20 km/h. a)suppose that the car has 10 such batteries. how long(hours)could …
  7. physics

    A car is designed to get its energy from a rotating flywheel (solid disk) with a radius of 1.00 m and a mass of 600 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to …
  8. physics

    A car has a flywheel ( a diks of R=0.2m and uniformly distributed mass M=100kg) that can convert 25% of the rotational kinetic energy into translational kinetic energy. The mass of the car is 1000kg ( including flywheel). Suppose the …
  9. physics

    The figure below shows a train with 3 compartments only. Each of the compartments has a mass of 30 tons . Two of them are motor cars while the other one is a trailer car. Each of the motor cars provides a driving force F. Suppose the …
  10. Physics

    A 1000-kg car has four 10-kg wheels. What fraction of the total kinetic energy of the car is due to rotation of the wheels?

More Similar Questions