I think you misunderstand Vo. If there were no acceleration, you'd have x=Vo*t, and it would not slow down at all.
The equation you have is right, but Vo = 33.7, its starting speed.
93.3 = 33.7t + 1/2 (-2.9)t^2
t = 3.2126 or 20.029
Why two answers? Which is right?
Think of the situation. After 3.2126 seconds the boat has reached the buoy.
But it has not stopped. A while later it stops and then comes back again (acceleration keeps reducing the velocity until it becomes negative). After 20.029 seconds, the boat is back at the buoy.
A speed boat moving at 33.7 m/s approaches a
no-wake buoy marker 93.3 m ahead. The pilot
slows the boat with a constant deceleration of
2.9 m/s
2
by reducing the throttle.
How long does it take the boat to reach the
buoy?
current work done:
x = Vot + (1/2)at^2
93.3 = 0(t) + (1/2)(-2.9)t^2
t = 8.0215
however when I submit that its wrong.
What do I do?
1 answer
1 answer