An object is at rest at (3 ,0 ,3 ) and constantly accelerates at a rate of 7/5 m/s^2 as it moves to point B. If point B is at (5 ,3 ,5 ), how long will it take for the object to reach point B? Assume that all coordinates are in meters.

1 Answer
Jul 17, 2017

The time is =2.43s

Explanation:

The distance AB is

s=sqrt((5-3)^2+(3-0)^2+(5-3)^2)

=sqrt(4+9+4)

=sqrt17m

We apply the equation of motion

v^2=u^2+2as

The initial velocity is u=0ms^-1

The acceleration is a=7/5ms^-2

Therefore,

v^2=0+2*7/5*sqrt17

v^2=11.54

v=sqrt(11.54)=3.4ms^-1

To determine the time, we apply the equation of motion

v=u+at

t=v/a

t=3.4/(7/5)=2.43s