Does a body in orbit have acceleration even if its speed remains constant? Explain you answer in DEETAIL.
Yes, it does. Acceleration is expressed using a vector. This means that it doesn't only have a magnitude, it also has a certain direction (as does the velocity). When a body is in orbit, the MAGNITUDE of it's velocity stays constant, but the DIRECTION of the velocity is constantly changingn (the direction of the velocity is always tangent to the circular path).
Therefore, in order for the velocity to be able to change (in direction), there needs to be a certain acceleration. The magnitude of this acceleration equals v²/r where v is the spead of the body and r is the distance of the body to the earth (or other body it is circling). The acceleration vector is always pointed to the center of the circular orbit path.