A v vs t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t=5s the acceleration of the ball is zero. We know that at t=5s,
a) the curve is not crossing the time axis
b) the velocity of the ball is not changing
c) the slope of the curve is nonzero
d) the curve is at v=0, t=0
Physics - drwls, Monday, October 13, 2008 at 2:17am
I assume you know that when the acceleration is zero, the velocity is not changing
Physics - Jimmy, Monday, October 13, 2008 at 2:36am
i think b is correct.. but what makes "a" incorrect?
Physics - drwls, Monday, October 13, 2008 at 2:52am
When t=5, you are not crossing the velocity (vertical) axis. If you were crossing the time axis, the velocity would be zero.
It is not impossible for velocity and acceleration to be zero at the same time, asymptotically. But if you are crossing the time axis, velocity must be changing with time. If acceleration is zero, you are not crossing the time line. So I agree (a) is OK also
Physics - Ron, Monday, October 13, 2008 at 8:52pm
but there is only one correct answer
Physics - drwls, Tuesday, October 14, 2008 at 5:05am
Not this time. Flip a coin