A stone of mass 2.6 kg is tied to the end of a string and is swung with constant speed around a horizontal circle with a radius of 0.52 m. If it makes two complete revolutions each second, its acceleration is:.
a. 82.11 m/s^2
b. 42.70 m/s^2
c. 5.13 m/s^2
d. 6.54 m/s^2
e. 20.53 m/s^2

Anne applies a force on a toy car and makes it move forward. what can be said about the forces acting on the toy car at the moment anne applies the force?

What is the coefficient of kinetic friction μk between the block and the tabletop?

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.