2. consider a situation where change in momentum come from a change in mass rather than that coming from a change in velocity of an object: rocket propulsion. the propelling gases exert force on the rocket. the gases are expelled at a rate of r = 1300 kg/s with a speed of v = 4.5 × 104 m/s. a) what is the mass expelled in time ∆t. label this mass ∆m. b) how much momentum does the mass carry, in terms of ∆t, r, and v. c) use the relationship between the average force and change in momentum to obtain the expression for the average force in terms of r and v and calculate its value.

Iwould think it is temperature, silica, oxides (gases)

Distance covered, s = 8ft - 4ft = 4 ftinitial velocity, u = 34 ft/sthe acrobat is moving upwards and therefore, a = -g = -9.81 m/s^2 = 32.19 ft/s^2applying equation of motion; s = ut -1/2gt^2then,4 = 34t -1/2*32.19t^24 = 34t - 16.095t^2rearranging; -16.095t^2 + 34t - 4 = 0solving the quadratic equation; t = {-34 +/- sqrt [34^2 - 4(-16.)]}/2(-16.095) = 1.06 +/- 0.93 = 0.13 or 1.99the acrobat will take 0.13 seconds to be at 8 ft above the ground. additionally, once at the maximum height, the acrobat will move down and be at the same spot (that is height) after 1.99 seconds moving down.

Cvelocity of the