A cricket ball of mass 'm' is thrown upword with some intial speed.if the air resistence is neglected,what forces are acting on the ball when it reaches (a)half its maximum height and (b)igs maximum height ?
Gravity is the only force acting on the mass m, neglecting air friction.
Gravitational fore
To determine the forces acting on the cricket ball at different heights during its upward motion, we need to consider the forces present in this scenario.
(a) When the ball reaches halfway up its maximum height:
At this point, the ball is still moving upward, but its velocity is decreasing. The forces acting on the ball are the gravitational force and the air resistance (assuming neglecting air resistance), both of which act in opposite directions.
- Gravitational Force (Weight): The ball experiences a downward force due to gravity, which is equal to its weight. The weight is given by the equation W = mg, where m is the mass of the ball and g is the acceleration due to gravity.
- Air Resistance: Since air resistance is neglected, this force can be ignored.
(b) When the ball reaches its maximum height:
At its maximum height, the ball momentarily comes to rest before it starts to fall. The forces acting on the ball are the gravitational force and the normal force.
- Gravitational Force (Weight): The ball experiences a downward force due to gravity, which is equal to its weight.
- Normal Force: As the ball comes to rest momentarily, the normal force (acting opposite to the gravitational force) becomes the upward force on the ball. The normal force arises from the contact between the ball and the surface supporting it.
Remember, without air resistance, the only significant force acting on the ball is the gravitational force.
To summarize:
(a) At half its maximum height: Gravitational Force (Weight) is acting downward.
(b) At its maximum height: Gravitational Force (Weight) is acting downward, and the Normal Force is acting upward.
Keep in mind that this explanation assumes ideal conditions with no air resistance. In reality, air resistance does exist, and its presence would affect the forces acting on the ball.