physics

posted by .

An elevator is being lifted up an elevator shaft at a constant speed by a steel cable. All fricional effects are negligible. In this situation,forces on the elevator are such that?:

A.the upward force by the cable is greater than the downward force of gravity
B. the upward force by the cable is smaller than the downward force of gravity
C.None of these: the elevator goes up because the cable is being shortened,not because an upward force is exerted on the elevator by the cable
D. the upward force of the cable is greater than the sum of the downward force of gravity and downward force due to the air
E. the upward force of the cable is equal to the downward force of gravity

Would it be choice A or C?

  • physics -

    There is no acceleration up or down
    F = m a
    so
    Net force is zero
    m g down = cable tension up
    so
    E

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    A cable lifts a 1370 kg elevator at a constant velocity for a distance of 42 m. What is the work done by each of the following?
  2. Physics

    Safety engineers estimate that an elevator can hold 20 persons of 65 kg average mass. The elevator itself has amass of 450 kg. Tensile strength tests show that the cable supporting the elevator can tolerate a maximum force of 2.94e4 …
  3. physics

    how do i solve for this..? please write out the equation for me to understand..:) an elevator weighing 2.00 * 10^5 N is supported by a steel cable. what is the tension in the cable when the elevator is accelerated upward at a rate
  4. physics

    An elevator weighing 2.00*10^5 N is supported by a steel cable. What is the tension in the cable when the elevator is accelerated upward at a rate of 3.00 m/s^2?
  5. Physics

    An elevator manufacturing company is stress-testing a new elevator in an airless test shaft. The elevator is traveling at an unknown velocity when the cable snaps. The elevator falls 2.50 meters before hitting the bottom of the shaft. …
  6. Physics

    An elevator weighing 10 000N is supported by a steel cable. Determine the tension in the cable when the elevator is accelerated upward at 3.0 m/s2 A) 7.0kN B) 10.0 kN C)11.6 kN D) 13.1 KN E) 40.0 kN
  7. Physics

    An elevator is lifted up by a thick steel cable. While the elevator is moving upwards with a decreasing velocity, a. the upward force on the elevator by the cable is greater than the downward force of the Earth b. the amount of upward …
  8. PHYSICS

    WORKER ARE LOADING EQUIPMENT INTO A FREIGHT ELEVATOR AT THE TOP FLOOR OF A BUILDING HOWEVER THEY OVERLOAD THE ELEVATORAND THE WORN CABLE SNAPS THE MASS OF THE LOADED ELEVATOR AT THE TIME OF THE ACCIDENT IS 1600KG..AS THE ELEVATOR FALLS,THE …
  9. physics

    An 8000 kg elevator is supported by a steel cable. If the acceleration of the elevator is 1.4 m/s^2 upward, then find the tension in the cable.
  10. Physics

    A steel cable of cross sectional area 2.5 cm^2 supports a 1000kg elevator. The elastic limit of the cable is 3 x 10^8 Pa. If the stress in the cable is not to exceed 20 percent of the elastic limit, then find the maximum upward acceleration …

More Similar Questions