Answer:
A. when the mass has a displacement of zero
Explanation:
The velocity of a mass on a spring can be calculated by using the law of conservation of energy. In fact, the total energy of the mass-spring system is equal to the sum of the elastic potential energy (U) of the spring and the kinetic energy (K) of the mass:
where
k is the spring constant
x is the displacement of the mass with respect to the equilibrium position of the spring
m is the mass
v is the velocity of the mass
Since the total energy E must remain constant, we can notice the following:
- When the displacement is zero (x=0), the velocity must be maximum, because U=0 so K is maximum
- When the displacement is maximum, the velocity must be minimum (zero), because U is maximum and K=0
Based on these observations, we can conclude that the velocity of the mass is at its maximum value when the displacement is zero, so the correct option is A.
To minimize neutron leakage from a reactor, the ratio of the surface area to the volume should be a minimum. For a given volume V the ratio of the sphere will be 
.
We know that the surface area and volume of the sphere is given by:
Therefore, the ratio between the surface area and the volume for the sphere will be:
Equating the volume to the constant c, we will find the value of 
.
Substituting the value of r in the ration between surface area and volume, we get:
Calculating the constants, we get:
Hence, the ration between surface area and volume is
To learn more about surface area and volume of sphere, refer to:
brainly.com/question/4387241
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Answer:
v₂ = 70 m / s
Explanation:
For this exercise let's use Bernoulli's equation
where subscript 1 is for the top of the mountain and subscript 2 is for Tuesday's level
P₁ + ½ ρ v₁² + ρ g y₁ = P₂ +1/2 ρ v₂² + ρ g y₂
indicate that the pressure in the two points is the same, y₁ = 250 m, y₂ = 0 m, the water in the upper part, because it is a reservoir, is very large for which the velocity is very small, we will approximate it to 0 (v₁ = 0), we substitute
ρ g y₁ = ½ ρ v₂²
v₂ = 
let's calculate
v₂ = √( 2 9.8 250)
v₂ = 70 m / s
Explanation:
When doing this calculation manually, the formula of conversion that you need to use is yd / 1.0936 = m and this is the same formula used by the online calculator. For instance, 2yd = 1.83m and 15yd = 13.72m.
So 200 yards is (200 / 1.0936)
which is 182.88 Meters
Hope it helps..
The force of gravity is the only force that keeps a pendulum in motion. both the force increases the speed of the pendulum on the downswing and decreases it's speed on its upswing.
