A force of 8 N will be required.
<h3><u>Explanation:</u></h3>
Mechanical advantage is defined as the ratio of output force from a system to the input force into the system. A machine which has the mechanical advantage more than 1 means it requires less force to give more force as output. Similarly, when the mechanical advantage for the machine is less than 1,it means more force is required to give to achieve a less one.
Here in the question, the mechanical advantage of the pulley is 2.
Output force required to pull the sack of potatoes upto kitchen is 16N.
Mechanical advantage = Output force / input force.
Or, 2= 16 / input force.
So input force = 
So a force of 8 N will be required to pull the pulley.
Answer: Selective breeding
Explanation:
Selective breeding or artificial breeding is a process that allows humans to select parents in plants and animals that have desirable traits. Such parents are bred to produce offspring that have desirable traits from both parents. Humans have bred many species of plants and animals to improve the quality of plant and animal yields in terms of crops, milk, meat, eggs, and other derivatives.
Answer:
The question lacks options, the options are:
A. understand the viewpoint of other people.
B. realize that the term heavy describes an object one way and the term big describes it another way
C. understand that six ounces of liquid in a jar and six ounces in an elongated tube are equal.
The answer is C
Explanation:
Piaget proposed the theory of cognitive development, which talks about how human intelligence is developed. Piaget worked with Children because he believed they played a significant role in the development of cognitive intelligence. Based on his work, he proposed four stages of cognitive development viz: sensorimotor, preoperational, concrete operational and formal operational stages.
However, in the preoperational stage, Piaget described children between ages 2-7 as being in this stage of cognitive development where they are yet to comprehend mental logic. One characteristics of this stage is CONSERVATION, which is the ability to know that changing a substance's appearance doesn't change the properties of that substance. Piaget proposed that Children between the ages of 2-7 lacked this conservative characteristics.
He performed an experiment where he used two beakers with the same amount of liquid. He then emptied the contents of one of the previous beakers into a new beaker with different shape (longer). Piaget was able to notice that Children at the pre-operational stage were unable to understand that the contents of the two beakers (longer one and previous beaker) were still the same despite the beaker has been changed.
Hence, according to Piaget, a child has acquired the cognitive skill of conservation when he/she is able to understand that six ounces of liquid in a jar and six ounces in an elongated tube are equal.
