Straw polls are considered to be a form of biased sampling. An example of a straw poll is an unofficial vote like who you would like to be the President without actually casting your ballot.
Answer:
polystyrene is a good insulater so less heat will escape from the cup and it will keep it warm.
the cup helps it become more insulated
X2 = 60
/ 2 / 2
x = 30
Plus or minus square root 60
Answer:
Conditions under which the belt and pulleys are operating – The friction between the belt and pulley may decrease substantially if the belt happens to be muddy or wet, as it may act as a lubricant between the surfaces.
Explanation:
I hope that this would be helpful
If the force moving an object points at least partially in the opposite direction of the objects motion, the work is considered to be negative.
<u>Explanation:
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Work done is the measure of displacements caused on an object by the amount of force acting on it. The work done can be positive or negative. If the direction of force acting on an object is along the direction of motion of the object then the work done is positive.
This is because, in this case the external force is helping the object to continue its state of motion. So, if the force acting on the object is in completely opposite or partially opposite direction to the direction of motion of the object, it will stop or slow down the motion of the object.
This kind of force will have negative direction to the motion of the object and hence the work done will also be negative.
