In a real system of levers, wheel or pulleys, the AMA (actual mechanical advantage) is less than the IMA (ideal mechanical advantage) because of the presence of friction.
In fact, the IMA and the AMA of a machine are defined as the ratio between the output force (the load) and the input force (the effort):

however, the difference is that the IMA does not take into account the presence of frictions, while the AMA does. As a result, the output force in the AMA is less than the output force in the IMA (because some energy is dissipated due to friction), and the AMA is less than the IMA.
Answer:
Pure research is conducted without any specific goal in mind. Applied research is conducted in order to solve a specific and practical problem, unlike pure research. Hope this helped.
Answer:
Option (B)
Explanation:
A lift chart usually refers to a graphical representation that is mainly used in order to improve the drawbacks of a mining model by making a comparison with any random guess, and also helps in determining the changes that occur in terms of lift scores.
It describes the binary classification of the problems associated with the mining activity. This type of chart is commonly used to differentiate the lift scores for a variety of models, and picking the best one out of all.
Thus, the correct answer is option (B).
Answer: D.) 39,200 J
Via the equation of potential energy PE = mgh where m is mass, g is the average gravity on earth and h is the height. In this case m = 400 kg, g = 9.8, h = 10 m thus:

P.E.= 39,200 Joules