Abeam of electrons (with unspecified energy) is partially transmitted through a thin ti foil a) from a reliable source, find the mass density (at room temp.) and molar mass of this element. calculate the density of atoms n (in atoms/cm3, or just cm) d. b) for a foil of thickness t-72 nm , the transmitted electron beam has 43% of the incident-beam intensity. determine the mean free path length л (in nm) for scattering in in (at this energy). c) determine the total atomic scattering cross section o, for an atom at this energy. use appropriate units

You throw a baseball directly upward at time t = 0 at an initial speed of 12.3 m/s. what is the maximum height the ball reaches above where it leaves your hand? at what times does the ball pass through half the maximum height? ignore air resistance and take g = 9.80 m/s2.

The substances that are necessary for producing of certain hormones and that store and transport vitamins

Astudent throws a water balloon with speed v0 from a height h = 1.76 m at an angle θ = 21° above the horizontal toward a target on the ground. the target is located a horizontal distance d = 9.5 m from the student’s feet. assume that the balloon moves without air resistance. use a cartesian coordinate system with the origin at the balloon's initial position. (a) what is the position vector, rtarge t, that originates from the balloon's original position and terminates at the target? put this in terms of h and d, and represent it as a vector using i and j. (b) in terms of the variables in the problem, determine the time, t, after the launch it takes the balloon to reach the target. your answer should not include h. (c) create an expression for the balloon's vertical position as a function of time, y(t), in terms of t, vo, g, and θ. (d) determine the magnitude of the balloon's initial velocity, v0, in meters per second, by eliminating t from the previous two expressions.