Urgent: when a bat hits a ball, the impulse is

a)the change in velocity multiplied by force*
b) the mass multiplied by force
c) the mass multiplied by acceleration
d) the force multiplied by the time the objects are in contact

*i think it's a

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th

Using proper grammar, spelling, and punctuation, write at least one 5 sentence paragraph describing 3 ways we use the elements of the electromagnetic spectrum (ems) in our everyday lives.

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)