Physics Problem: Forces! Can someone help me with this?

Question

I need help with this problem please.. answer + explanation so I can understand it appreciated... Thanks!

A textbook is suspended on a spring scale in an elvator. Of the following, the scale shows the highest reading when the elevator:

a) moves upward with increasing speed
b) moves upward with decreasing speed
c) remains stationary
d) moves downward with increasing speed
e) moves downward at constant speed

Thank you! also...
the same problem above, but separate question with these choices:

a) moves downward with increasing speed
b) moves downward with decreasing speed
c) remains stationary
d) moves upward with increasing speed
e) moves upward at constant speed

Answer 1

In every case, the acceleration of the elevator is added to the acceleration of gravity g, taking sign (direction) into account. So when the elevator is increasing speed upwards, its acceleration will add to g, increasing the spring reading. If the elevator is decreasing speed upwards, its acceleration subtracts from g and reduces the scale reading. Non-accelerating motion (constant speed or stationary) does not change anything, so the scale reading does not change. Reverse the sense (sign) for downward motions: increasing speed downwards subtracts from g. This should allow you to answer both parts of the question.

Answer 2

Before i answer the question, consider the following cases:
1. The book of weight W is suspended by a cord from a spring scale in an elevator. There are two forces acting on the book, the pull of gravity W and the upward pull T of the cord. At equilibrium(at rest). T is equal to W. The scale reading gives the magnitude of the force T which is equal to the weight W of the book.
2. When the elevator moves upward, the book is accelerating in the same direction. Since acceleration is not equal to zero, then there is an unbalanced force acting on the load. The tension of the cord T is greater than the weight W.

According to Newton's second law:
unbalanced force = ma
The unbalance force is acting upward and is equal to the difference between two forces;that is

unbalanced force = T - W
therefore,
T - W = ma
T = W + ma
The equation shows that the scale reading T is greater than the weight of the book. The scale reading is the apparent weight of the book.

3. If the elevator is moving downward, the W must be greater than T. The unbalanced force in this case is acting downward.
The equation for T may be obtained as follows:

unbalanced F = ma
unbalanced F = W - T
W - T = ma
T =W - ma
The magnitude of T is obtained from the scale reading. The apparent weight of the book is less than its true weight.

so from this cases you can now determine which is the answer of the first question

Answer 3

the scale would shows the highest reading when it moves upward with increasing speed.

as the elevator moves upwards with increasing speed, acceleration of elevator is considered, hence produce an upward force and due to newtons third law of motion (when a first body exerts a force on a second body the second body exerts an equal and opposite force on the first) textbook produce normal reaction
therefore the magnitude of spring scale will increase gruadually when the velocity of spring is increasing at an increasing rate , wheareas magnitude of spring scale will stay constant but magnitude of higher reading then bcde when velocity of spring is increasing at a constant rate.

As for part two? ? wats the question?

Answer 4

Sum Fx = zero and Sum Fy = zero Sum Fx = F1,x + F2,x + F3,x = zero + forty four cos 60 + F3,x = 22 + F3,x = zero. So, F3,x = -22 N. Sum Fy = F1,y + F2,y + F3,y = 33 + forty four sin 60 + F3,y = 33 + forty four sin 60 + F3,y = zero So, F3,y = -seventy one N. F3 = sqrt [ F3,x ^two + F3,y ^two ] = sqrt [ (-22)^two + (-seventy one)^two ] = seventy four N. Direction of F3 = a hundred and eighty + tan^(-one million) (seventy one/22) = a hundred and eighty + seventy three = 253 deg.

Answer 5

ARENT YOU SUPPOSE TO BEA PHYSIC