Identify the action and reaction forces in the following situations: a) Earth attracts the Moon, b) a boy kicks a football, c) a
1 answer:
You might be interested in
Answer:
a) Fg = -27.4 N
b) Fnet = 5.2 N
c) a = 1.9 m/s2
Explanation:
a)
- There are two forces acting on the ball, one directed upward (assuming this direction as positive, along the y-axis) which is the tension on the string (lifting force), and another aimed downward, which is the attractive force due to gravity.
- Applying the Newton's Universal Law of Gravitation to a mass close to the surface of the Earth (in this case the ball), we can take the acceleration due to gravity like a constant, that we call by convention g, equal to -9.8 m/s2.
- So, we can write the following expression for Fg:
b)
- The net force on the ball, will be just the difference between the lifting force (32.6 N) and the force due to gravity, Fg:
c)
- According Newton's 2nd Law, the acceleration caused by a net force on a point mass (we can take the ball as one) is given by the following expression: