Answer:

Explanation:
given,
frequency of tuba.f = 64 Hz
Speed of train approaching, v = 8.50 m/s
beat frequency = ?
using Doppler's effect formula

v_s is the velocity of the source
v is the speed of sound, v = 340 m/s
now,

f' = 65.64 Hz
now, beat frequency is equal to



hence, beat frequency is equal to 1.64 Hz
Complete Question
A small metal sphere, carrying a net charge q1=−2μC, is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of q2= -8μC and mass 1.50g, is projected toward q1. When the two spheres are 0.80m apart, q2 is moving toward q1 with speed 20ms−1. Assume that the two spheres can be treated as point charges. You can ignore the force of gravity.The speed of q2 when the spheres are 0.400m apart is.
Answer:
The value 
Explanation:
From the question we are told that
The charge on the first sphere is 
The charge on the second sphere is 
The mass of the second charge is 
The distance apart is 
The speed of the second sphere is 
Generally the total energy possessed by when
and
are separated by
is mathematically represented

Here KE is the kinetic energy which is mathematically represented as

substituting value


And U is the potential energy which is mathematically represented as

substituting values


So


Generally the total energy possessed by when
and
are separated by
is mathematically represented

Here
is the kinetic energy which is mathematically represented as

substituting value


And
is the potential energy which is mathematically represented as

substituting values


From the law of energy conservation

So


Answer:
B. changing by a constant amount each second
Explanation:
thats my answer
Answer:
Mechanical waves are waves that require a medium. This means that they have to have some sort of matter to travel through. These waves travel when molecules in the medium collide with each other passing on energy. One example of a mechanical wave is sound.
Force acting during collision is internal so momentum is conserve
so (initial momentum = final momentum) in both directions
Two cars collide at an icy intersection and stick together afterward. The first car has a mass of 1150 kg and was approaching at 5.00 m/s due south. The second car has a mass of 750 kg and was approaching at 25.0 m/s due west.
Let Vx is and Vy are final velocities of car in +x and +y direction respectively.
initial momentum in +ve x (east) direction = final momentum in +ve x direction (east)
- 750*25 + 1150*0 = (750+1150)
Vx
initial momentum in +ve y (north) direction = final momentum in +ve y direction (north)
750*0 - 1150*5 = (750+1150)
Vy
from here you can calculate Vx and Vy
so final velocity V is
<span>V=<span>(√</span><span>V2x</span>+<span>V2y</span>)
</span>
and angle make from +ve x axis is
<span>θ=<span>tan<span>−1</span></span>(<span><span>Vy</span><span>Vx</span></span>)
</span><span>
kinetic energy loss in the collision = final KE - initial KE</span>