Answer:
nπ + π/2 for any integer n
Explanation:
Since destructive interference occurs every odd multiple of half wavelength, that is π/2, 3π/2, 5π/2 where the interference is half wavelength and in general, (n + 1/2)π where n is an integer. So, nπ + π/2 for any integer n
Answer:
Options A and B.
Explanation:
Gravitational acceleration, initial height, intial speed and time are required to determine final speed. The option D is incorrect, since speed varies in time. Option C is dimentionally wrong.
The correct strategy is calculating the initial height from option B. Later, substituting time in equation A to derive an expression of the final velocity in terms of position. Hence, the required equations are options A and B.
Answer:
t = 5.89 s
Explanation:
To calculate the time, we need the radius of the pulley and the radius of the sphere which was not given in the question.
Let us assume that the radius of the pulley (
) = 0.4 m
Let the radius of the sphere (r) = 0.5 m
w = angular speed = 150 rev/min = (150 × 2π / 60) rad/s = 15.708 rad/s
Tension (T) = 20 N
mass (m) = 3 kg each


Substituting values:

Answer:
4 s
Explanation:
u = 19.6 m/s, g = 9.8 m /s^2
Let the time taken to reach the maximum height is t.
Use first equation of motion.
v = u + at
At maximum height, final velocity v is zero.
0 = 19.6 - 9.8 x t
t = 19.6 / 9.8 = 2 s
As the air resistance be negligible, is time taken to reach the ground is also 2 sec.
So, total time taken be the ball to reach at original point = 2 + 2 = 4 s
if the velocity of the car reduces from 70km/h to 50km/h then the speed of the car will be equal to the speed of the lorry...
thus the relative velocity will be 0