Answer:
3.46 seconds
Explanation:
Since the ball is moving in circular motion thus centripetal force will be acting there along the rope.
The equation for the centripetal force is as follows -
Where, 
is the mass of the ball, 
is the speed and 
is the radius of the circular path which will be equal to the length of the rope.
This centripetal force will be equal to the tension in the string and thus we can write,
and, 
Thus, 
m/s.
Now, the total length of circular path = circumference of the circle
Thus, total path length = 2πr = 2 × 3.14 × 2 = 12.56 m
Time taken to complete one revolution = 
= 
= 3.46 seconds.
Thus, the mass will complete one revolution in 3.46 seconds.
The desire for positive reinforcement.
Answer:
False
Explanation:
It is located in the little dipper whose stars are more faint.
Answer:
B.) by interfering with sound waves
Explanation:
As we know that the interference of sound waves is of two types
1). constructive interference
2). destructive interference
now we know that constructive interference means the resultant intensity will be more than the intensity of interfering waves as here two waves are in same phase.
In destructive interference the resultant of two waves is given by the minimum resultant of the intensity as here the phase of two waves are opposite to each other.
So we will say that
here in case of noise cancelling headphones we know that the phase of noise is always made in opposite phase with the sound which is used to cancelled the noise.
This will reduce the noise and we will get a clear sound
Given values:
Mass of the steel ball, m = 100 g = 0.1 kg
Height of the steel ball, h1 = 1.8 m
Rebound height, h2 = 1.25 m
a. PE= mgh
0.1 x 9.8 x 1.8 =
1.764 Joules
b. KE = PE ->
1.764 Joules
c. KE= 1/2 mv square
so v = square root 2ke/m
square root 2 x 1.764/ 0.1
= 5.93 m/s
d. KE=PE=mgh square
0.1 x 9.8 x 1.21 =
1.186 joules
velocity of rebond is square root 2x 1.186/ 0.1 = 4.87 m/s
