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Why does gravitational potential energy have a negative value?

A point in a gravitational field has an associated gravitational potential. It is defined as the work done required to bring a unit mass from a point an infinite distance to that point in the field. At an...

Answered by Joseph P. • Physics tutor

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explain how the body regulates blood sugar concentration

blood sugar concentration is controlled through a negative feedback loop*. When blood glucose concentration is high, insulin made in the pancreas is released into the bloodstream. Glucose is taken into ce...

Answered by Nishi A. • Biology tutor

2226 Views

The distinction between the imperfect tense and the passé composé

The imperfect tense and the passé composé are both past tenses which are used in different situations. The imperfect tense is used in three main cases:Habitual actions-> What

Answered by Assunta S. • French tutor

1624 Views

Calculate 3/5 + 5/8. Give your answer as a mixed number in its simplest form.

To answer this question, create the least common denominator possible. In this instance, the LCD is 40. (I know this because multiples of 5 only end in 0 and 5, and 40 is the lowest multiple of 8 that mee...

Answered by Emily P. • Maths tutor

14370 Views

Describe how B-lymphocytes respond when they are stimulated by antigens.

When B-lymphocytes are stimulated by antigens, they first divide by mitosis to form clones, some of which become plasma cells that secrete antibodies, others become memory B-cells which can be stimulated ...

Answered by • Biology tutor

20130 Views