Answer:
Explanation:
For third normal mode of vibration
l = , λ is wavelength , l is length of string .
.4 =
λ = .267 m
velocity =
T is tension and m is mass unit length
m = .5 x 10⁻³ / 40 x 10⁻²
= .00125 kg / m
Putting the values
velocity =
= 253 m /s
frequency
= velocity / λ
= 253 / .267
= 947.5 Hz .
Answer:
No. Touching a live electric current is never a good idea.
Explanation:
Answer:
A. Underground coal mining is dangerous because of possible tunnel collapse and possible methane gas explosions.
Explanation:
Dangers of underground coal mining include asphyxiation, methane gas poisoning, tunnel collapse and explosions of methane gas, a highly flammable gas. Methane explosions occur since this gas is a byproduct of coal. This explosion can cause tunnel collapse.
Answer:
Explanation:
Velocity is defined as the variation of the position of a body, object or particle with time.
In addition, the unit in the International System of Units (SI) for velocity is meters per second (), if we square it, we will have:
Answer:
8N and 32N
Explanation:
Given that a light board, 10 m long, is supported by two sawhorses, one at one edge of the board and a second at the midpoint. A small 40-N weight is placed between the two sawhorses, 3.0 m from the edge and 2.0 m from the center.
To calculate the forces that are exerted by the sawhorses on the board, we must consider the equilibrium of forces acting on the board.
Let the two upward forces produce by the saw horses be P1 and P2
Assuming that the weight is negligible
Sum of the upward forces = sum of the downward forces.
P1 + P2 = 40 ....... (1)
Also, the sum of the clockwise moment = sum of the anticlockwise moments.
Let's assume that the board is uniform. The weight will act at the centre.
Taking moment at the centre:
P1 × 5 + 40 × 2 = 0
P1 = 40 / 5
P1 = 8N
Substitute P1 into equation 1
8 + P2 = 40
P2 = 40 - 8
P2 = 32N