If they are both pushing with the same force but in opposite directions,
and if there are no other forces on the box besides them pushing, then
the net force on the box is zero and it just lays there, as if there were
no forces on it at all.
Answer:
391.67Hz
Explanation:
The fundamental frequency formula in string is expressed as;
Fo = V/2L
V is the velocity of the wave = 329m/s
L is the length of the string = 42cm = 0.42m
Substitute
Fo = 329/2(0.42)
Fo = 329/0.84
Fo = 391.67Hertz
Hence the fundamental frequency of a mandolin string is 391.67Hz
Answer:
more time to change the momentum of falling rocks
Explanation:
Momentum is related to "mass in motion." So, if an object is moving, then it has momentum as it has its mass in motion. The amount of momentum is dependent upon how much and how fast the object is moving.
If an object is moving slowly, it means that the object is losing momentum.
Nets used to catch falling boulders on the side of rocky hillside roadways are more effective than rigid fences because their breakage is reduced by more time to change the momentum of falling rocks.
To solve this problem we will consider the concepts related to the normal deformation on a surface, generated when the change in length is taken per unit of established length, that is, the division between the longitudinal fraction gained or lost, over the initial length. In general mode this normal deformation can be defined as

Here,
= Change in final length
and the initial length 
PART A)




PART B)




PART C)




Therefore the rank of this deformation would be B>C>A
(a)
The formula is:
∑ F = Weight + T = mass * acceleration
as the elevator and lamp are moving downward, I choose downward forces to be
positive.
Weight is pulling down = +(9.8 * mass)
Tension is pulling up, so T = -63
Acceleration is upward = -1.7 m/s^2
(9.8 * mass) + -63 = mass * -1.7
Add +63 to both sides
Add (mass * 1.7) to both sides
(9.8 * mass) + (mass * 1.7) = 63
11.5 * mass = 63
mass = 63 / 11.5
Mass = 5.48 kg
(b)
Since the elevator and lamp are going upward, I choose upward forces to be
positive.
Weight is pulling down = -(9.8 * 5.48) = -53.70
Acceleration is upward, so acceleration = +1.7
-53.70 + T = 5.48 * 1.7
T = 53.70 + 9.316 = approx 63 N
The Tension is still the same - 63 N since the same mass, 5.48 kg, is being accelerated
upward at the same rate of 1.7 m/s^2