Answer:
The friction force is 250 N
Explanation:
The desk is moving at constant velocity. This means that its acceleration is zero: a = 0. Newton's second law states that the resultant of the forces acting on the desk is equal to the product between mass (m) and acceleration (a):
In this case, we know that the acceleration is zero: a = 0, so also the resultant of the forces must be zero:
(1)
We are only interested in the forces acting along the horizontal direction, since it is the direction of motion. There are two forces acting in this direction:
- the pull, forward, F = 250 N
- the friction force, backward, 
Given (1), we have
So the force of friction must be equal to the pull:
A thermogram<span> enables the human eye to "see" light in the infrared range of the electromagnetic spectrum.</span>
Answer:
Answer:
Option B
Explanation:
Option B talks about how the frequency of the wave increases the shorter it's wavelengths
Answer:
I = 9.82 10⁻⁷ W / m²
Explanation:
The intensity of the sound wave is the energy of the wave between the order per unit area of the same
I = P / A = E / T A
the energy is calculated by integrating the mechanical energy in a period, where the mass is changed by the density and ‘s’ is the amplitude of the sound wave
I = ½ ρ v (w s)²
I = ½ 1.35 328 (2π 530 2.00 10⁻⁸)²
I = 221.4 (4.435 10⁻⁹)
I = 9.82 10⁻⁷ W / m²
Answer:
Explanation:
radius of gyration of wheel k then
k² = r²/2
r² = 2 k²
r = √2 k
= 1.414 x .3 m
r = .4242 m
Moment of inertia of wheel
= mass x radius of gyration ²
= 25 x .3 x .3
= 2.25 kg m²
Friction force acting on it ( sliding )
= μmg , μ being coefficient of kinetic friction
This friction force will create linear acceleration in forward direction
Acceleration produced
= μg
= .6 x 9.8
= 5.88 m / s ²
This will also rotate the wheel , angular acceleration being
linear acceleration / radius
= 5.88 /.4242
= 13.86 radian / s²
