Answer:
Explanation:
Given
mass of bus along with travelers travelling in North direction is 
speed of bus towards North 
mass of bus travelling in South direction is 
speed of bus 
mass of each Passenger in south moving bus 
Momentum of North moving bus



Momentum with south moving bus


For total momentum to be towards south
should be greater than 0
thus for least value of n



Answer:
This will require 266.9 of heat energy.
Explanation:
To calculate the energy required to raise the temperature of any given substance, here's what you require:The mass of the material, m The temperature change that occurs, ΔT The specific heat capacity of the material,
c
(which you can look up). This is the amount of heat required to raise 1 gram of that substance by 1°C.
Here is a source of values of
c for different substances:
Once you have all that, this is the equation:
Q=m×c×ΔT(Q is usually used to symbolize that heat required in a case like this.)For water, the value of c is 4.186g°C So, Q=750×4.186×85=266=858=266.858
Answer:
Option (A) is correct.
Explanation:
A horizontal rope has a length of 5 m and a mass of 0.00145 kg. If a pulse occurs on this string, generating a wavelength of 0.6 m and a frequency of 120 Hz. The tension to which the string is subjected is
mass of string, m = 0.00145 kg
Frequency, f = 120 Hz
wavelength = 0.6 m
Speed = frequency x wavelength
speed = 120 x 0.6 = 72 m/s
Let the tension is T.
Use the formula

Option (A) is correct.