Answer:
0.14 J
Explanation:
The maximum velocity is the amplitude times the angular frequency.
vmax = Aω
ω = vmax / A
ω = (3.2 m/s) / (0.06 m)
ω = 53.3 rad/s
For a spring-mass system:
ω = √(k / m)
ω² = k / m
k = ω²m
k = (53.3 rad/s)² (0.050 kg)
k = 142 N/m
The elastic potential energy is:
EE = ½ kx²
EE = ½ (142 N/m) (0.044 m)²
EE = 0.14 J
Answer:
They will not stop at same elevation
for v=10m/2 => h=5.1m
for v=20m/2 => h=20.4m
Explanation:
If we neglect the effects of friction in the calculations the energy if the system must be conserved. The car energy can be described as a combination of kinetic energy and potential energy:
The potential energy is due to the gravitational forces and can be describes as:
Where g is the gravitation acceleration, m the mass of the car, and h the elevation. This elevation is a relative quantity and any point of reference will do the work, in this case we will consider the base of the hill as h=0.
The kinetic energy is related to the velocity of the car as:
As the energy must be constant E will be always constant, replacing the expressions for kinetic and potenctial energy:
In the base of the hill we have h=0:
When the car stops moving we have v=0:
This two must be equal:
solving for h:
Lets solve for the two cases:
for v=10m/2 => h=5.1m
for v=20m/2 => h=20.4m
As you can see, when the velocity is the double the height it reaches goes to four times the former one.
Answer:
An echo is a sound caused by the reflection of sound waves from a surface back to the listener.
Explanation:
Answer:
(A) As it moves farther and farther from Q, its speed will keep increasing.
Explanation:
When a positive charge Q is fixed on a horizontal frictionless tabletop and a second charge q is released near to it then according to the Coulombs law the force acting on it decreases with the square of the distance between them.
Mathematically:
where:
r = distance between the charges
permittivity of free space
By the Newtons' second law of motion if the we know that the acceleration is directly proportional to the force applied. So as the distance between the charges increases the its acceleration also decreases therefore now the charge feels less acceleration but still continues to accelerate with a fading magnitude.
Answer:
You can determine which charge has the solid by rubbing plastic and fur, and bringing near the plastic and the solid to determine if they are repeled or attracted. If they are repeled, the solid is charged negatively and if they are attracted, the solid is charged positively.
Explanation:
In order to determine the charge of the solid (negative or positive) using a piece of plastic and fur, you have to rubb the plastic with the fur (this is charging by friction)
Negative charges are transferred from the fur to the piece of plastic, therefore the plastic is charged negatively.
Then, you have to bring near the solid and the plastic. If them are repeled, it means that the solid is charged negatively (Because similar charges are repeled)
If them are attracted, it means that the solid is charged positively (Because opposite charges are attracted)