A stone is thrown vertically upward with a speed of 15m/s.what is the acceleration of the stone in its highest point of its motion?
The acceleration is
a = -g = -9.8 m/s^2
at all times the stone is in the air.
It does not depend upon the initial thrown velocity.
The minus sign is there because the acceleration is in a downward direction.
Acceleration is "g" at each point of the trajectory
To determine the acceleration of the stone at the highest point of its motion, we need to consider the physics concept of projectile motion.
In projectile motion, the only force acting on the stone once it is in the air is the force of gravity, which always acts downward. This force causes the stone to slow down as it rises until it reaches its maximum height and then accelerates back downward. The acceleration due to gravity is constant and is approximately 9.8 m/s² on the surface of the Earth (assuming no air resistance).
At the highest point of its motion, the stone momentarily comes to rest before accelerating downward. This means that the stone's velocity at that point is zero. Since acceleration is the rate of change of velocity, we can conclude that the acceleration of the stone at its highest point is equal to the acceleration due to gravity, which is approximately 9.8 m/s².