posted by .

14)The cable of the elevator you are riding in breaks and the elevator begins to freefall at terminal velocity to the ground. Why would jumping up right before impact still not help you survive?

A)Because your overall inertia is down
B)Because you would be accelerating up
C)Because you are weightless
D)It would help you survive

I got C

15)If a horizontal force applied on a resting object is greater than the force of friction, the object will.

A)move at a constant velocity
B)accelerate in the direction of the applied force
C)move backwards
D)stay at rest

I got B

  • physics -

    14)da ans is a
    15)its b

  • physics(2nd opinions please) -

    anyone else agree?

  • physics -

    In 14 the best answer is D, although in it won't work well.

    By jumping up you reduce the velocity w.r.t. to the ground a bit, so when the bottom of the lift hits the ground and stops, you are moving toward the ground at a lower speed.

    In 15 all options are wrong. You are supposed to answer B) but strictly speaking that is not right because the applied force does not need to point in the direction opposite to the friction force.

  • physics -

    I agree with Iblis on 14. You can slightly reduce your velocity relative to the Earth at impact by jumping up just before impact. The effect might be helpful when falling one story, but not much more than that, or when the elevator is falling at terminal velocity (as here), which would be huge. They probably want you to answer A

    In 15, Iblis is refering to the possiblity of friction with a directional bias, such as one might abtain when sliding on a grooved surface where the groves are inclined to the applied force. They want you to answer B, but is not always true.

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

    12)It is summertime and two boys cannot wait for winter. One boy exerts a 70N horizontal force as he pushes his 58 kg friend standing on a snowboard across a cement sidewalk at a constant speed. What is the coefficient of kinetic between …
  4. Physics

    An elevator cable breaks when a 950 kg elevator is 23 m above a huge spring (k = 2.3×105 N/m) at the bottom of the shaft. (a)Calculate the work done by gravity on the elevator before it hits the spring. (b) Calculate the speed of …
  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

    The single cable supporting an unoccupied elevator breaks when the elevator is at rest at the top of a 155 m high building. With what speed does the elevator hit the ground?
  7. Physics

    While an elevator of mass 2681 kg moves upward, the tension in the cable is 29.4 kN. (a) What is the acceleration of the elevator?

    While an elevator of mass 2681 kg moves upward, the tension in the cable is 29.4 kN. (a) What is the acceleration of the elevator?
  9. physics

    An elevator is travelling upwards at 15m/s2 and the hoisting cable is cut when it is 40 m from the ground. Determine the maximum height reached by the elevator & the velocity just before it hits the ground.
  10. Physics

    An 80 kg man stands in an elevator. What force does the floor of the elevator exert on the man if a) the elevator is stationary?

More Similar Questions