A block of mass M=1.0 kg is dragged over a horizontal surface by a force F=20.0N. The block is displaced a distance d=10.0 m, the friction force Ff is 5.0 N. What is the work done by the weight Fg?
To find the work done by the weight Fg, we first need to calculate the gravitational force acting on the block. The weight of an object can be found using the formula:
Fg = m * g
where Fg is the weight, m is the mass, and g is the acceleration due to gravity (which is approximately 9.8 m/s^2 on Earth).
Given that the mass of the block is M = 1.0 kg, we can calculate:
Fg = 1.0 kg * 9.8 m/s^2 = 9.8 N
The work done by the weight Fg can be calculated using the formula:
Wg = Fg * d * cos(θ)
where Wg is the work done by the weight, Fg is the force of gravity, d is the displacement, and θ is the angle between the force and the displacement.
In this case, the force Fg is acting vertically downward, while the displacement d is horizontal. This means the angle θ between the force and the displacement is 90 degrees, and the cosine of 90 degrees is 0.
Therefore, the work done by the weight Fg is:
Wg = Fg * d * cos(θ) = 9.8 N * 10.0 m * cos(90 degrees) = 0
So, the work done by the weight Fg is 0.