What is the potential energy of a 3 kg rock sitting at the top of a 21 meter high cliff?

618.03 J

Explanation:

Potential energy can be calculate using the following formula.

PE=m*g*h

where m is the mass, g is the acceleration due to gravity and h is the height.

In this situation, we have a 3 kilogram rock on a 21 meter high cliff. Therefore, the mass is 3 kg and the height is 21 m.

On Earth, the acceleration due to gravity is 9.81 m/s^2.

m=3 kg

h=21 m

g=9.81 m/s^2

Substitute these values into the formula.

PE=3*9.81*21

Multiply all the numbers together

PE=63*9.81

PE=618.03

The potential energy is 618.03 kg m^2/s^2, or 618.03 Joules

The audience knows Mrs. Hale has the dead bird in her coat pocket, but the men in the story do not.

Explanation:

Dramatic irony is a literary device that is used to show when the audience/ readers of the story know something which the characters in the story did not know. This form of dramatization gives an advantage to the audience.

In the play "Trifles" by Susan Glaspell revolves around the death of Mr. Wright. This feminist drama shows the two other female characters, Mrs. Peters and Mrs. Hale sympathize with Mrs. Wright who had been accused and arrested for the murder of her husband.

In part two of the play, what the men/policemen did not know was that Mrs. Hale and Mrs. Peters had found a dead bird in the sewing box, a symbol of Mr. Wright's repressive actions of his wife's freedom. The bird had been a source of happiness for the lonely woman but her controlling husband killed it which led Mrs. Wright to finally snap and kill her husband. The two women decided to get rid of the evidence which would have further proved her guilt. Both women knew what it was like to be oppressed by men and so, their sympathy for the accused lady led to their act of hiding the evidence for the crime.