Answer:
The elastic potential energy stored in the compressed piece is 5.47 J
Explanation:
Given;
elastic potential energy stored, E = 14 J
initial compression, x = 0.240m
The elastic potential energy stored in a spring is given as;
E = ¹/₂Kx²
where;
E is elastic potential energy
K is the spring constant
x is the compression
K = 2E / x²
K = (2*14) / (0.24²)
K = 486.11 N/m
When the spring is cut into three equal pieces, and one of pieces is then compressed by 0.150m, the energy stored in this piece is calculated as;
E = ¹/₂Kx²
E = ¹/₂(486.11)(0.15²)
E = 5.47 J
Therefore, the energy stored in one of the cut pieces compressed by 0.150m is 5.47 J
Answer:
After throwing the object the, the velocity of the man is 13.98 m/s
Explanation:
Given:
Let,
mass of man, m1 = 74 kg
mass of box, m2 = 13 kg
Initial velocity u = 11 m/s (initially both are together hence initial velocity will be same for both)
Final velocity of man = v1
Final velocity of box = v2 = -6 m/s (the velocity is recoil velocity therefore it is negative)
To Find:
Final velocity of man,after throwing the object = v1 = ?
Solution:
Recoil velocity:
It is the backward velocity experienced.
Here recoil velocity is the backward velocity experience while throwing the box behind.Hence the velocity of the box is negative 6 m/s.
The recoil velocity is the result of conservation of linear momentum of the system. Therefore we will follow the law of conservation of momentum.
Law of conservation of momentum :
Total momentum of an isolated system before collision is always equal to total momentum after collision
substituting the values which are given above we get
Therefore, After throwing the object the, the velocity of the man is 13.98 m/s
Answer:
b. False
Explanation:
The Bernoulli's equation is given by;
Divide through by the density of the fluid and acceleration due to gravity (ρg), to obtain energy per unit weight of the fluid known as head;
where;
is pressure head
h is datum head (mechanical energy due to height of the fluid)
is velocity head (mechanical energy due to velocity of the fluid)
Thus, the mechanical energy of a fluid per unit weight of the fluid, measured relative to the bottom of the channel is datum head.
The correct option is "b. False"
Answer:
Refractive index of material is 2
Explanation:
If speed of light in medium is v then speed of light in vacuum will be 2v
Refractive index = v1/v2 = 2v/v = 2