Question

2. MP HW P2.58 (Refer to example 2.10, p47) A hotel elevator ascends 200m with maximum speed of 5m/s. Its acceleration and deceleration both have a magnitude of 1.0m/s a. How far does the elevator move while accelerating to full speed from rest? b. How long does it take to make the complete trip from bottom to top? A) i) Draw a motion diagram and show the velocity vectors and the acceleration vectors on the motion diagram; ii) Shovw the coordinate system and all variables you are going to use iii) List known and unknown values in SI units below B) Sketch the position, velocity and acceleration versus time graphs. Clearly label the starting and ending instants of time of its acceleration (both speeding up and slowing) in each graph. Position-time graph Velocity-time graph Acceleration-time graplh C) Find an equation to calculate the displacement the elevator moves while accelerating to full speed from rest. D) Calculate the time the elevator takes to make the complete trip from bottom to top.

Answer 1

As acceleration and deceleration both has same value . So distance moved while accelerating is same as the distance moved while deceleration.

From rest the elevator reaches to maximum speed and again decelerates and finally comes to rest.

Calculation and explanation is shown below.