A body explodes and splits into three pieces, the first piece has mass of 1.25kg and velocity of [ 30 -10 ]m/s, the second piece has main of 3.25kg and velocity of [ -17 10 ]m/s the third piece has velocity of [ 35.5 40 ]m/s. What is the mass of the third piece. What was the total mass of the body before the explosion.

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.

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?