$(a)$ Define circular motion.
$(b)$ "Uniform circular motion is an accelerated motion". Justify this statement with reason.
$(c)$ An artificial satellite is moving in a circular orbit of radius $42250 \, km$. Calculate its speed if it takes $24 \, h$ to revolve once around the Earth.

$(a)$ When a body moves along a circular path, it is said to be in circular motion.
$(b)$ Uniform circular motion is considered an accelerated motion because the direction of the velocity vector changes at every point along the path, even though the magnitude (speed) remains constant. Since acceleration is defined as the rate of change of velocity, a change in direction constitutes acceleration.
$(c)$ The distance covered in one revolution is the circumference of the circular orbit, given by $2 \pi r$.
Distance $= 2 \times 3.14 \times 42250 \, km = 265330 \, km$.
Time taken $(t) = 24 \, h$.
Speed $= \frac{\text{Distance}}{\text{Time}} = \frac{265330 \, km}{24 \, h} \approx 11055.42 \, km/h$.