Answer:
Part a)

Part b)

Explanation:
Part a)
As we know that initially the position vector is r
then the same magnitude position vector is rotated by 40 degree angle
so displacement magnitude is the magnitude of change in position vector
so it is given as




Part b)
now we need to find the direction of the displacement vector
so let say it makes an angle with x axis so we have



Answer: The correct answer is "the pitch drops to a lower pitch once the ambulance passes by Juan".
Explanation:
Doppler effect is the phenomenon in which there is an increase or decrease in the frequency when there is relative motion between the source and listener.
Pitch depends on the frequency. if the frequency increases then pitch increases.
When the source and the listener are moving towards each other then there is increase in the frequency. When the source and the listener are moving away each other then there is decrease in the frequency.
In the given problem, Juan is standing on the street. An ambulance moves toward him and then passes by the pitch drops to a lower pitch once the ambulance passes by Juan.
The intensity of a light in a surface follows the inverse square law formula which can be mathematically expressed as,
I = k/d²
where I is intensity, d is distance, and k is the proportionality constant. For us to increase the intensity, we should lower the distance from the source to the surface.
M1 descending
−m1g + T = m1a
m2 ascending
m2g − T = m2a
this gives :
(m2 − m1)g = (m1 + m2)a
a =
(m2 − m1)g/m1 + m2
= (5.60 − 2)/(2 + 5.60) x 9.81
= = 4.65m/s^2
Answer:
Magnetic field, B = 0.004 mT
Explanation:
It is given that,
Charge, 
Mass of charge particle, 
Speed, 
Acceleration, 
We need to find the minimum magnetic field that would produce such an acceleration. So,

For minimum magnetic field,



B = 0.004 T
or
B = 4 mT
So, the magnetic field produce such an acceleration at 4 mT. Hence, this is the required solution.