An object is at rest at (2 ,1 ,5 )(2,1,5) and constantly accelerates at a rate of 7/6 m/s76ms as it moves to point B. If point B is at (6 ,3 ,7 )(6,3,7), how long will it take for the object to reach point B? Assume that all coordinates are in meters.

1 Answer
Jul 31, 2017

t = 2.90t=2.90 "s"s

Explanation:

NOTE: I'll assume the given acceleration is 1/515 "m/s"^2m/s2, not 1/515 "m/s"m/s.

We're asked to find the time tt it takes an object to travel a certain distance with a given constant acceleration.

To do this, we can use the equation

Deltax = v_(0x)t + 1/2a_xt^2

where

  • Deltax is the distance it travels, which can be found using the distance formula:

Deltax = sqrt((2-6)^2 + (1-3)^2 + (5-7)^2) = 4.90 "m"

  • v_(0x) is the initial velocity, which is 0 since it started from rest

  • t is the time (we're trying to find this)

  • a_x is the constant acceleration (given as 7/6 "m/s"^2)

Plugging in known values, we have

4.90 "m" =0t + 1/2(7/6color(white)(l)"m/s"^2)t^2

t = sqrt((4.90color(white)(l)"m")/(7/12color(white)(l)"m/s"^2)) = color(red)(ul(2.90color(white)(l)"s"