Answer:
If the observer is stationary but the source moves toward the observer at a speed vs, the observer still intercepts more waves per second and the frequency goes up. This time it is the wavelength of the wave received by the observer that is effectively shifted by the motion, rather than the speed.
Answer: 
Explanation:
According to the described situation we have the following data:
Horizontal distance between lily pads: 
Ferdinand's initial velocity: 
Time it takes a jump: 
We need to find the angle
at which Ferdinand jumps.
In order to do this, we first have to find the <u>horizontal component (or x-component)</u> of this initial velocity. Since we are dealing with parabolic movement, where velocity has x-component and y-component, and in this case we will choose the x-component to find the angle:
(1)
(2)
(3)
On the other hand, the x-component of the velocity is expressed as:
(4)
Substituting (3) in (4):
(5)
Clearing
:

This is the angle at which Ferdinand the frog jumps between lily pads
Answer:

Explanation:
Given:
- charge on the alpha particle,

- mass of the alpha particle,

- strength of a uniform magnetic field,

- radius of the final orbit,

<u>During the motion of a charge the magnetic force and the centripetal forces are balanced:</u>


where:
v = velocity of the alpha particle



Here we observe that the velocity of the aprticle is close to the velocity of light. So the kinetic energy will be relativistic.
<u>We firstly find the relativistic mass as:</u>



now kinetic energy:



Answer:
Explanation:
We shall apply the formula for velocity in case of elastic collision which is given below
v₁ = (m₁ - m₂)u₁ / (m₁ + m₂) + 2m₂u₂ / (m₁ + m₂)
m₁ and u₁ is mass and velocity of first object , m₂ and u₂ is mass and velocity of second object before collision and v₁ is velocity of first velocity after collision.
Here u₁ = 22 cm /s , u₂ = - 14 cm /s . m₁ = 7.7 gm , m₂ = 18 gm
v₁ = ( 7.7 - 18 ) x 22 / ( 7.7 + 18 ) + 2 x 18 x - 14 / ( 7.7 + 18 )
= - 8.817 - 19.6
= - 28.4 cm / s