8 When a person stands on tiptoe (a strenuous position). The total gravitational
force on the body, F is supported by the force n exerted by the floor on the toes
of one foot. I is the force exerted by the Achilles tendon on the foot and R is the
force exerted by the tibia on the foot. Find the values of T, R, and when F=
n=700 N.

The least penetrating form of radiation is

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.

Astudent pushes a 40-n block across the floor for a distance of 10 m. how much work was applied to move the block? a. 4 j b. 40 j c. 400 j d. 4000 j