Answer:
Explanation:
Given
Wavelength of first timpani 
Frequency corresponding to this Wavelength

where 


Wavelength of Second timpani 
Frequency corresponding to this Wavelength


Beat frequency 
Beat frequency 
so approximately 7 beats per second
Answer:
the answer is option A = photoelectric effect
Explanation:
If the threshold frequency of a metal is lower than the energy of X-rays, then photoelectric effect will happen.
Answer:
1.944m_s²
Explanation:
First convert speed from km/h to m/s the use the formula a=v-u
t
Answer:
zero
Explanation:
q = 6.4 nC = 6.4 x 1 0^-9 C
d = 16 cm = 0.16 m
r = 16 / 2 = 8 cm = 0.08 m
Electric field at P due to the charge placed at A
Ea = k q / r^2
Ea = ( 9 x 10^9 x 6.4 x 10^-9) / (0.08 x 0.08) Towards right
Ea = 9000 Towards right
Electric field at P due to the charge placed at B
Eb = k q / r^2
Eb = ( 9 x 10^9 x 6.4 x 10^-9) / (0.08 x 0.08) Towards left
Eb = 9000 Towards left
The magnitude of electric field is same but teh direction is opposite, so the resultant electric field at P is zero.