Answer:
The velocity
Explanation:
For a mass-spring system, the total mechanical energy is constant during the motion. The total mechanical energy is sum of the elastic potential energy, U, and the kinetic energy, K:
where
k is the spring constant
x is the displacement
m is the mass
v is the velocity
Since E must remain constant, we see that when x increases, v decreases, and vice-versa. Therefore, when x (the displacement) is at maximum, v (the velocity) is at minimum (more precisely, it is zero).
Answer:
The kinetic energy remains same and gravitational potential energy increases.
Explanation:
KINETIC ENERGY:
As, we know that the kinetic energy depends upon the speed of the object. Hence, the kinetic energy is given as:
K.E = (1/2)mv²
where,
m = mass
v = speed
K.E = Kinetic Energy
Since, the friction is ignored, therefore the speed of roller coaster will remain same.
Therefore, its Kinetic Energy will also remain same.
POTENTIAL ENERGY:
The potetial energy od a body depends upon its height, as follows:
P.E = mgh
where,
P.E = potential Energy
m = mass
g = acceleration due to gravity
h = height
As, the roller coaster moves up hill its height increases.
Therefore, its potential energy will also increase.
hence, the correct option is:
<u>The kinetic energy remains same and gravitational potential energy increases.</u>
Answer:
b. greater because the column of blood between the arm and leg has hydro-static pressure
Explanation:
The use of the "depth" equation explains it very well.
Answer:
3. both are true.
Explanation:
Energy increses with decrease in wavelenght.
For photoemission to occur, a threshold energy barrier must be broken.
Higher energy means more electrons will be emmited.
The electrons emmited will posses energy that is less than the incident energy by the value of the threshold energy.
So the higher the energy, the higher the energy possessed by the electrons.
Answer:
Fourier's laws
Explanation:
The problem can be solved if Fourier's laws for conductivity are applied as well,
(1)
where
A = heat transfer area (m2, ft2)
k = thermal conductivity of the material (W/m.K or W/m oC, Btu/(hr oF ft2/ft))
ΔT = temperature difference across the material (K or oC, oF)
s = material thickness (m, ft)
The thermal conductivity of concrete is k= 1.7
Since
1 dollar = 5 Kilowatt hours or 5000 watthours so
Time for 1 dollar = 5000/1256.64 = 3.978 hours or 3 hours 58 minutes