Use the concept of beat frequency to find the applicable final freqeuncy for 20Hz beat frequency.
Beat can be defined as 'the interference pattern between two sounds of slightly different frequencies0
The expression for beat frequency is given as

Where,
Final frequency
Initial frequency
The beat frequency for us is 25Hz and the initial frequency is 240Hz, then

Being an absolute value, two values are possible, both in addition and subtraction:

The two possible values are


We know that the change in momentum is equals to the product of force and time that is impulse (
). Therefore, we need to determine the value of that the water is in air by using the second equation of motion,

Here, u is initial velocity which is zero.
.
Thus, impulse

From Newton`s second law,

Therefore, impulse

Given,
and 
Substituting these values, we get
Change in momentum = impulse
.
That's ONLY true when the pendulum is hanging
in the center position and not moving.
Answer:14 m/s
Explanation:
Kinetic energy(ke)=175J
Momentum(M)=25kgm/s
Speed=v
Mass=m
Ke=(m x v x v)/2
175=(mv^2)/2
Cross multiply
175 x 2=mv^2
350=mv^2
Momentum=mass x velocity
25=mv
m=25/v
Substitute m=25/v in 350=mv^2
350=25/v x v^2
350=25v^2/v
v^2/v=v
350=25v
v=350/25
v=14 m/s
Answer:
the correct answer is D
Explanation:
In this exercise, the vectors are in the same west-east direction, so we can assume that the positive direction is east and perform the algebraic sum.
R = δ + ε
where
δ = 2.0 m
ε = 7.0 m
the positive sign indicates that it is heading east
R = 2.0 + 7.0
R = 9.0 m
the direction is east
the correct answer is D