Answer:
B) A stack of books is carried at waist level across a room
Explanation:
Work is defined as:
where
F is the force applied
d is the displacement of the object
is the angle between the direction of the force and of the displacement
From the formula, we see that the work done is zero when the force and the displacement are perpendicular to each other. Let's now analyze each situation:
A) A bookcase is slid across carpeting. --> work is done, because the force that pushes the bookcase is in the same direction of the displacement
B) A stack of books is carried at waist level across a room. --> no work is done, because the force to carry the book is vertical, while the displacement of the books is horizontal
C) A chair is lifted vertically with respect to the floor. --> work is done, because the force that lifts the chair is vertical, and the displacement is vertical as well
D) A table is dropped onto the ground. --> work is done, because the force of gravity (that makes the table falling down) is vertical and the displacement of the table is also vertical.
7. The nineteenth amendment protects the right to vote of 18 year old women.
8.The 24th amendment eliminated poll taxes and increases voting rights in the United States.
9.National voter Registration allowed the option for adults to register vote when they obtain or renew a driver's license.
10.Three steps in voting process are registering to vote, preparing to vote and casting a ballot.
11.The statement that was not an effect of the United States Supreme Court's ruling in Bush vs Gore is Tennessee's electoral collage votes went to Al Gore.
12.The general election requires the United States choose a president
13.The type of election that is held to fill a public office that is left vacant when an official resigns is special election.
14.The position that a person actually vote for when a voter chooses a candidate for president is an elector in the elector college.
15.A possible candidate for president would form an exploratory committee to see how much support he or she can expect.
Straight upward
the ball moves in the forward direction with your walking speed at all times. If you want the ball to land in your hand when it comes back down, you should toss the ball straight upward.
<h3>What is Projectile motion ?</h3>
Projectile motion is the motion of an object thrown (projected) into the air.
- After the initial force that launches the object, it only experiences the force of gravity. The object is called a projectile, and its path is called its trajectory
- A projectile can be a thrown ball, a bullet or a springboard diver ... Except for air resistance, the forward velocity of any projectile is constant and is equal to the initial velocity when it was released.
Learn more about Projectile motion here:
brainly.com/question/27116954
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Nothing happens to the mirror.
However, if the ray is within some suitable range of
wavelengths, the ray is reflected from the mirror's surface.
