Answer:
125.09 Hz
Explanation:
Given : A person stands 5.20 from one speaker and 4.10 m away from the other speaker.
Distance between the speakers is 5.20 - 4.10 =1.10 m
We know that
For destructive interferences
n . λ / 2
where n =1,3,5,7....
Therefore difference between the speakers is
5.10 - 4.20 = 1 X 0.5 λ
λ = 2.2
Given velocity of sound is V = 344 m/s
Therefore frequency, f = 
= 
= 156.36 Hz
Now, the third lowest frequency is given by
λ = (5.20-4.10) X 5 X 0.5
= 2.75 m
Therefore frequency, f = 
= 
= 125.09 Hz
Therefore third lowest frequency is 125.09 Hz
Answer:
The length and the magnification of this telescope are 41 cm and 0.108.
Explanation:
Given that,
Focal length of first lens f= 4.0 cm
Focal length of other lens f'= 37 cm
We need to calculate the length of the telescope
Using formula of length

Put the value into the formula

We need to calculate the magnification of the telescope
Using formula of the magnification

Put the value into the formula


Hence, The length and the magnification of this telescope are 41 cm and 0.108.
Answer:
a) v= 2.1 m/s
b) ω = 0.807 rad/s
Explanation
Conceptual analysis :
The dog and the merry-go- round describes a circular motion, then, the following formulas apply :
Formula (1)
v = ω *r Formula (2)
Where:
: Centripetal acceleration(m/s²)
v: linear speed or tangential (m/s)
r : radius of the circle (m)
ω : angular speed ( rad/s)
Data
r= 2.6 m
= 1.7 m/s²
Problem develpment
a) We replace data in the formula 1 to calculate the dog's linear speed(v):


v= 2.1 m/s
b)We replace data in the formula 2 to calculate the angular speed of the merry-go- round (ω).
v = ω *r
2.1 = ω *2.6
ω = 2.1/2.6
ω = 0.807 rad/s
Answer: maximum height= 40.8m
Explanation: shown in the attachment.
Goodluck
Answer:
a) v, v
b) 2mv^2
c) Elastic collion
Explanation:
(a) The velocity of the second particle after the collision is (v2x,v2y)=(v,−v). From momentum conservation in x-direction
Here x, y represent direction.They are not variable. 1 and 2 represent before and after.
2vm=v1xm+v2xm, we find v1x=v.
From momentum conservation in y-direction
0 =v1ym+v2ym, we findv1y=v.
(b) By energy conservation principle
Before: K=1/2m(2v)^2=2mv^2.
After: K=1/2m(v^2(1x)+v^2(1y))+12m(v22x+v22y)=2mv^2
(c) The collision is elastic