Answer
given,
mass of the piano = 170 kg
angle of the inclination = 20°
moves with constant velocity hence acceleration = 0 m/s²
neglecting friction
so, force required to pull the piano
F = m g sin θ
F = 170 × 9.81 × sin 20°
F = 570.39 N
so, force required by the man to push the piano is F = 570.39 N
The correct answer is
C. Light can pass through Object B faster than it can pass through Object A.
In fact, the index of refraction of a material is defined as:

where c is the speed of light in vacuum and v is the speed of light in the material. Rearranging the equation, we can write the speed of light in the material as:

So we that, the smaller the refractive index n, the greater the speed of light in the material, v. In this problem, object B has lower refractive index than object A, so light travels faster in object B.
Answer:
440hz
Explanation:
saxophone a plays at 430hz and a frequency of 5 beats per second can be heard so saxophone b is playing at a frequency 10hz louder than saxophone A making it 440hz
Answer:
UV light is more powerful as it has greater energy.
Explanation:
The energy propagated by electromagnetic waves ( light ) through vacuum or medium is known as electromagnetic radiation.
The frequency/wavelength range of electromagnetic radiation is known as electromagnetic spectrum. The electromagnetic spectrum ranging from gamma ray to radio waves.
Frequency range of UV light = ( 8 x 10¹⁴ to 3 x 10¹⁶ ) Hz
Frequency range of Microwaves = ( 300 x 10⁶ to 300 x 10⁹ ) Hz
Ratio of UV light to Microwaves = (
to
)
= ( 2.66 x 10⁶ to 1 x 10⁸ )
Energy of electromagnetic radiation is given by the relation:
E = hν
Here h is plank's constant and ν is frequency.
UV light is more powerful than Microwaves as frequency of UV light is greater than frequency of microwaves. Thus, by the above equation, the energy of UV light is more than energy of Microwaves.