"Constant velocity" is practically a definition for zero acceleration.
Im not so sure but it should be the
instantaneous speed
if you are going slow, there wont be much of an effect or not any damage.
Answer:
A. The bird watcher followed the south trail a distance of five kilometers in 45 minutes.
Answer:
a) 70 N, b) b. Each initially applied a force bigger than static friction to get the box moving and accelerating, then when the desired final speed was achieved they reduced the force to make the net force zero.
Explanation:
a) A constant speed means that magnitude of friction force is equal to the magnitude of the external force. The friction force is directly proportional to the normal force, which is equal to the weight of the box. Therefore, the magnitude of the force is 70 N.
b) Alice used initially a greater force to accelerate the box up to needed speed and later reduced the external force to keep speed constant. The right choice is option b.