<span><span>Velocity is a vector, and the initial and final ones are in opposite directions. There must have been acceleration in order to change the direction of motion.</span>
A) No. The initial and final velocities are the same. This is all wrong, and not the correct choice. It's "Yes", and the initial and final velocities are NOT the same.
B) Yes. The ball had to slow down in order to change direction.
This is poor, and not the correct choice. The "Yes" is correct, but the explanation is bad. Acceleration does NOT require any change in speed.
C) No. Acceleration is the change in velocity. The ball's velocity is constant.
This is all wrong, and not the correct choice. It's "Yes", there IS acceleration, and the ball's velocity is NOT constant.
D) Yes. Even though the initial and final velocities are the same, there is a change in direction for the ball.
This choice is misleading too. The "Yes" is correct ... there IS acceleration. The change in direction is the reason. The initial and final velocities are NOT the same. Only the speeds are. </span>
What is the acceleration of an object moving at a constant speed?
The Meaning of Constant Acceleration
The data table above show an object changing its velocity by 10 m/s in each consecutive second. This is referred to as a constant acceleration since the velocity is changing by a constant amount each second.
(a) An electron accelerated from rest through a potential difference of 100 V. The De Broglie wavelength in terms of potential difference is given by :
