Answer:
0.68 m
Explanation:
We know that the speed of sound in air is a product of frequency and wavelength. Taking speed of sound in air as 340 m/s
V=frequency*wavelength
Then wavelength is given by 350/500=0.68 m
Therefore, to repeat constructive interference at the listener's ear, a distance of 0.68 m is needed
Answer:
Like charges repel
Different charges attract
Explanation:
When particles of similar charges are brought together, they repel each other and increase the distance of separation. Repulsion occurs because both two electrons have negative electrical charge forcing their lines of force to repel. However, when particles of opposite charges are brought nearer to each other, they attract each other and reduce the distance of separation.
Answer:

Explanation:
The maximum velocity of an object moving in a curve beyond which it will slide off the curve is given by the relationship in equation (1);

where
is the coefficient of friction between the object and the surface of the curve, g is acceleration due to gravity and r is the radius of the curve.
Given;
v = 0.8m/s
g = 
r = ?

In order to solve for
, we can simply make it the subject of formula from equation (1) as follows;

since we were not given the value of r, we can just substitute other known values, then solve and leave the answer in terms of r.
Therefore;


Answer:
B. The presence of an unbalanced force(e.g friction) causes a moving object to stop.
Explanation:
As the friction is that force that can stop the sled upon reaching the levelled surface so the option b is correct.
Answer:
m₁ / m₂ = 1.3
Explanation:
We can work this problem with the moment, the system is formed by the two particles
The moment is conserved, to simulate the system the particles initially move with a moment and suppose a shock where the particular that, without speed, this determines that if you center, you should be stationary, which creates a moment equal to zero
p₀o = m₁ v₁ + m₂ v₂
pf = 0
m₁ v₁ + m₂ v₂ = 0
m₁ / m₂ = -v₂ / v₁
m₁ / m₂= - (-6.2) / 4.7
m₁ / m₂ = 1.3
Another way to solve this exercise is to use the mass center relationship
Xcm = 1/M (m₁ x₁ + m₂ x₂)
We derive from time
Vcm = 1/M (m₁ v₁ + m₂v₂)
As they say the velocity of the center of zero masses
0 = 1/M (m₁ v₁ + m₂v₂)
m₁ v₁ + m₂v₂ = 0
m₁ / m₂ = -v₂ / v₁
m₁ / m₂ = 1.3