Question
A courier is delivering a 5kg package to an office high in a tall building.
(a) What upwards force does the courier apply to the package when carrying it horizontally at a constant velocity of 2m/s into the building?
(b) The courier uses the elevator to reach the office. While the elevator (containing the courier who is holding the package) is accelerating upwards at 0.11m/s what upwards force is the courier applying to the package?
(c) When the elevator is travelling upwards at a constant speed of 6m/s what upwards force does the courier apply to the package?
(d) In order to stop at the correct floor the elevator accelerates downwards (decelerates) at a rate of 0.20m/s. What is the upwards force the courier applies to the package during the deceleration?
(a) What upwards force does the courier apply to the package when carrying it horizontally at a constant velocity of 2m/s into the building?
(b) The courier uses the elevator to reach the office. While the elevator (containing the courier who is holding the package) is accelerating upwards at 0.11m/s what upwards force is the courier applying to the package?
(c) When the elevator is travelling upwards at a constant speed of 6m/s what upwards force does the courier apply to the package?
(d) In order to stop at the correct floor the elevator accelerates downwards (decelerates) at a rate of 0.20m/s. What is the upwards force the courier applies to the package during the deceleration?
Answers
bobpursley
a. upward force equals the weight of the package, of course, mg
b. upward force equals weight plus accelerating force, mg+ma
c. same as b, but a is zero.
d. same as b, but a is now negative.
b. upward force equals weight plus accelerating force, mg+ma
c. same as b, but a is zero.
d. same as b, but a is now negative.