Answer:
Principal focus of a concave mirror. The principal focus of a concave mirror is a point on its principal axis to which all the light rays are parallel and close to the axis converge after reflection from the concave mirror.
Focal length of a concave mirror. The focal length of a concave mirror is the distance between its pole and the principal focus
The reflecting surface of a spherical mirror forms a part of a sphere. The centre of this sphere. This point is called the centre of curvature of the spherical mirror. Center of curvature can also be defined as the point in the centre of the sphere from which the mirror was sliced. It is represented by the letter C. Please note that the centre of curvature lies outside the mirror's reflecting surface. The centre of curvature of a concave mirror lies in front of it. However, it lies behind the mirror in case of a convex mirror.
If a concave mirror were thought of as being a slice of a sphere, then there would be a line passing through the center of the sphere and attaching to the mirror in the exact center of the mirror. This line is known as the principal axis.
Answer:
c. wavelength
Explanation:
The speed of the wave on the string is given by

Here, \mu is the mass per unit length and T is the tension in the string.
For the different thickness, the mass per unit length is different. Therefore, the wave speed is different in the two strings.
The frequency of the oscillations depends upon the oscillator. So, the frequency is same for the two strings by using same oscillator.
The frequency and speed relation is,
f= γλ
λ= f/γ
Since frequency is constant, the wavelength of the waves different as the speeds are different.
Answer:
163 N
Explanation:
The density of copper is about 8.96. The ratio of the weight in water to the weight in air is about 1-1/ρ, so is about 0.8884.
0.8884 × 184 N ≈ 163 N
The submerged weight is about 163 N.
The combined system of you + elevator has two forces, a combined force of gravity and the tension in the cable. Consider the normal force acting on you from the elevator: N = mg if the elevator is at rest or moving at constant velocity. N = mg + ma if the elevator has an upward acceleration.
V= fx lambda
lambda, or wavelength= v/f
=343/1395
=0.25 m.