8. A 0.5-kg ball has been thrown vertically upward. If we
ignore the air resistance, what are the direction and
size of each force acting on the ball while it is traveling
upward?
While the ball is traveling upward, there are two forces acting on it: the force of gravity and the force of the object's weight.
1. Force of gravity: The force of gravity always acts downward, towards the center of the Earth. This force is responsible for pulling the ball downward. Its size can be calculated using the equation F = mg, where F is the force of gravity, m is the mass of the ball (0.5 kg), and g is the acceleration due to gravity (approximately 9.8 m/s²).
F = (0.5 kg) * (9.8 m/s²) = 4.9 N
Therefore, the force of gravity acting on the ball while it is traveling upward is 4.9 Newtons (N) and directed downward.
2. Force of weight: The weight of an object is the force exerted on it due to gravity. Since gravity is always pulling objects downward, the weight is the force experienced by the object in the opposite direction. In this case, the weight of the ball is the same as the force of gravity calculated above: 4.9 N, directed downward.
To summarize:
- Force of gravity: 4.9 N, directed downward.
- Force of weight: 4.9 N, directed downward.
When a 0.5-kg ball is thrown vertically upward, the two main forces acting on it are gravity and the force applied by the person throwing the ball. Let's break down each force:
1. Gravity: The force of gravity always acts vertically downward, towards the center of the Earth. It is the force that pulls the ball back down to the ground. The size of the force due to gravity can be calculated using the formula F = mg, where "m" is the mass of the object and "g" is the acceleration due to gravity (which is approximately 9.8 m/s^2). So, for a 0.5-kg ball, the force of gravity would be F = (0.5 kg) * (9.8 m/s^2) = 4.9 N.
2. Applied Force: The person who throws the ball exerts an upward force on it. This force opposes the force of gravity and causes the ball to move upward. The size of the applied force depends on how forcefully the person throws the ball. Since the ball is thrown upward, the applied force will have a direction opposite to the force of gravity, meaning it is directed vertically upward.
So, to summarize:
- The force of gravity acts vertically downward with a size of 4.9 N.
- The applied force acts vertically upward, opposing gravity, and its size depends on how forcefully the ball is thrown.
Important Note: This explanation assumes that we are ignoring air resistance, which means that the effect of air friction on the ball's motion is not taken into account.