5. Two speakers are spaced 15 m apart and are both producing and identical sound wave. You are standing at a spot as pictured. What would be the frequency produced by the speakers create perfectly constructive interference? Assume n=1 and v=343 m/s
A. 213.04 Hz
B.256.70Hz
C.186.68Hz
D.233.14Hz
6.one brand of dog whistle claims a frequency of 25 kHz for its product. What is the wavelength of this sound (the speed of sound in air is 343m/s)
A.0.01372 m
B.0.02181 m
C.0.01748 m
D. 0.011654 m
7.When astronomers observe the spectra of distant galaxies, they notice that the hydrogen emission lines are shifted noticeably toward the red end of the visual spectrum, a phenomenon called red shift. Red is the lowest frequency of visible light. What does red shift indicate about the movement of distant galaxies?
A. The galaxies are moving toward us.
B. the galaxies are moving away from us
C. The galaxies are the same distance away from us as they always have been.
D. We cannot tell anything from this information.

connect the batteries in series and hope

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.