Ihave a question, how do you describe acceleration when an object is changing in speed?

Acceleration is the change of speed, usually faster, such as a car driving faster, from 40 mph to 50 mph. That is an acceleration of the car. So pretty much it is adding speed to current speed.

hope this helps

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.

explanation:

v=uf/(u-f)

= 5.-10/(5+10) convex lens has negative focal length