We know, Speed = Wavelength * Frequency
Speed = 32.4 * 3
Speed = 97.2 m/s
So, option D is your correct answer.
Hope it helped.
Use the inverse square law, thus if you move a distance of 3m away, the sound intensity decrease by 1/3^2= 1/9
No. Motion is the thing that when you're moving, you're in it.
But it IS possible for one person to say you're moving and another person to say you're not moving, both at the same time, and both of them are correct !
Answer:
Explanation:
During the first .8 s , the elevator is under acceleration . It starts from initial velocity u = 0 , final velocity v = 1.2 m /s , time = .8 s
v = u + at
1.2 = 0 + .8 a
a = 1.2 / .8
= 1.5 m /s²
During the acceleration in upward direction , let reaction force of ground on man be R .
Net force on man = R - mg
Applying Newton's 2 nd law
R - mg = ma
R = m ( g + a )
= 72 ( 9.8 + 1.5 )
= 813.6 N .
This reaction force will be measured by spring scale , so reading of spring scale will be 813.6 N .
i thinks answers is gap relutance increases linearly with magnetic density
