A1.5-kg playground ball is moving with a velocity of 3.0 m/s directed 30â° below the horizontal just before it strikes a horizontal surface. the ball leaves this surface 0.50 s later with a velocity of 2.0 m/s directed 60â° above the horizontal. what is the magnitude of the average resultant force on the ball?

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

Unpolarized light whose intensity is 1.19 w/ is incident on a polarizer. (a) what is the intensity of the light leaving the polarizer? (b) if the analyzer is set at an angle of = 41.0∘ with respect to the polarizer, what is the intensity of the light that reaches the photocell?

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer