Light is incident from air on the surface of a glass slab, which has an index of refraction of 2.5 In the air the light beam makes an angle of 40 degree with the normal to the surface. What is the angle of the beam with the normal in the glass?​

you would expect a sound wave to speed up. - b)

it was given as a lesson and guide for prayer.

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.