Given:
Effort (E) = 20 N
Load (L) = 160 N
Efficiency (η) = 75% = 0.75

Efficiency is defined as the ratio of output work to input work. In this case, the output work is the work done on the load and the input work is the work done by the effort.

Efficiency (η) = (Output work / Input work) * 100%

Output work = Load * Distance moved by the load
Input work = Effort * Distance moved by the effort

Since the distance moved by the load and the effort is the same, we can write:

Efficiency (η) = (Load * Distance moved) / (Effort * Distance moved) * 100%

Substituting the given values:

0.75 = (160 * Distance moved) / (20 * Distance moved) * 100%

Simplifying the equation:

0.75 = 8 * Distance moved / Distance moved * 100%

0.75 = 800 / Distance moved

Distance moved = 800 / 0.75

Distance moved = 1066.67 meters



The velocity ratio (VR) of a machine is defined as the ratio of the distance moved by the effort to the distance moved by the load.

Velocity Ratio (VR) = Distance moved by the effort / Distance moved by the load

In this case, the distance moved by the effort and the load is the same. Therefore:

Velocity Ratio (VR) = 1



Frictional force (F) is the force opposing the motion of the machine. It is the difference between the effort and the load.

Frictional Force (F) = Effort - Load

Substituting the given values:

Frictional Force (F) = 20 N - 160 N

Frictional Force (F) = -140 N (Negative sign indicates that the frictional force is acting in the opposite direction of the effort)



The law of the machine states that the effort required to overcome the load is directly proportional to the load.

Mathematically, we can write:

Effort = Load * Constant (K)

In this case, the frictional resistance of the machine is constant, which means that the effort required to overcome the load remains constant regardless of the load.

Therefore, the law of the machine is:

Effort = Constant (K)



Using the law of the machine, we can determine the effort required to run the machine at a load of 200 N.

Effort = Constant (K)

To find the value of the constant, we can use the given values:

20 N = 160 N * K

K = 20 N / 160 N

K = 0.125

Now, we can calculate the effort required for a load of 200 N:

Effort = 200 N * 0.125

Effort = 25 N

Therefore, the effort required to run this machine at a load of 200 N is 25 N.