The Girl with the Goalden Boot

Tuesday, January 17, 2006

 

Need some help with physics...

1. "If an object's speed remains constant, then its acceleration must be zero." Why is this statement false? Problem solved, thanks to Ashley! An object travelling at a constant speed may change its direction (like, an outside force acting on the object) without changing its speed. If there's a change in the direction of the object's path, then the acceleration can't be zero.

2. This one has to do with centripetal force & circular motion. Object A is further from the centre than object B. Does A have a greater centripetal force than B? And why? Just figured this one out. B has a greater centripetal force than A. Centripetal force is inversely proportional to radius...according to the F=mv²/r equation. I think.

Lola Nadal 7:39 PM