A box is pulled across a horizontal surface at a constant speed by a horizontal rope with tension T=30N. The coefficient of friction between the box and surface is uk = 0.05.

1. Calculate the work done by friction as the box moves 4 meters to the right.

i thought it would be .05 x 30 x 4 since work is F x D but it isn't

2. What is the mass of the box.

Multiply pulling force by distance for the work done.

Use the uk value to get the mass of the boss.

Friction force = M*g*uk

1. To calculate the work done by friction, you will need to multiply the force of friction by the distance the box moves. The force of friction can be found using the equation:

Frictional Force (Ff) = Coefficient of Friction (uk) x Normal Force (N)

In this case, the normal force N is equal to the weight of the box, and since the box is being pulled horizontally at a constant speed, the normal force will be equal to the gravitational force acting on the box:

N = Weight (W) = mass (m) x acceleration due to gravity (g)

The acceleration due to gravity is approximately 9.8 m/s^2.

Now, to find the mass of the box:

2. Since the weight of the box (W) is equal to the gravitational force acting on it, we can use the following equation:

W = mass (m) x acceleration due to gravity (g)

From the information given, we know that the tension force in the rope is T = 30 N. When the tension force is equal to the weight of the box, there is no vertical acceleration (the box is not lifted or lowered). Therefore, the weight of the box is equal to the tension force in the rope:

W = T = 30 N

Now, using this value in the equation above, we can solve for the mass of the box (m):

m = T / g

m = 30 N / 9.8 m/s^2