Speed Velocity and acceleration

Sir ir it true or false – “the speed of particle remains constant.this means that no unbalanced force acts on it.” (Purshkar  asks) Answer: If velocity remains constant, then we can say that no unbalanced force acts on it. If a body moves with uniform speed with its direction changing with time, as in the case [...]

Is law of conservation of energy violated here?

“When a body is moving with uniform speed on a rough surface under the application of a constant external force and an equal and opposite frictional force, the work done by both the forces should be equal. as a result, the net work done by both the forces should be zero. however, we find that [...]