A man pulls a 25kg sled a distance of 80 meters across a flat, snowy surface. He holds the handle of the sled at an angle of 30degrees with the ground. How much work does he do on the sled against the force of friction?(Assume the coefficient of sliding friction between the sled and the snow to be .1, and cos30=.87).
M*g*(1-sin30)*0.1*cos30*80
= 849 J
The M*g*(1-sin30) is the net downward force of the sled on the groud.
g = 9.8 m/s^2
To find the work done on the sled against the force of friction, we need to calculate the force of friction first. We can use the equation:
Frictional force = coefficient of friction * normal force
In this case, the normal force is equal to the weight of the sled, which can be calculated using the equation:
Normal force = mass * gravity
Given that the mass of the sled is 25kg, and the acceleration due to gravity is approximately 9.8 m/s^2, we can calculate the normal force as follows:
Normal force = 25 kg * 9.8 m/s^2
Normal force = 245 N
Next, we can calculate the force of friction using the equation:
Force of friction = coefficient of friction * normal force
Given that the coefficient of sliding friction between the sled and the snow is 0.1, we can calculate the force of friction as follows:
Force of friction = 0.1 * 245 N
Force of friction = 24.5 N
Now we can calculate the work done on the sled against the force of friction using the equation:
Work = force * distance * cos(angle)
In this case, the applied force is equal to the force of friction (since they are acting in opposite directions), the distance is 80 meters, and the angle is 30 degrees. Given that cos(30) is approximately 0.87, we can calculate the work as follows:
Work = 24.5 N * 80 m * 0.87
Work = 1690.4 Joules
Therefore, the man does approximately 1690.4 Joules of work on the sled against the force of friction.