. A small toy car having 300 grams of mass and going straight with an initial velocity of 13 m/s. When the toy car collides with an obstacle, a resistive force of 4 N acts upon it. The speed of the toy car reduced and reached 8 m/s. Draw its free body diagram and then find the time for the toy car to be into rest position?

On a cold day, when the air temperature is 0°c, you empty your lungs and take a deep breath, filling your lungs with 4.2 l of air. if you hold your breath until the temperature of the air in your lungs reaches 37°c, what is the volume of the air in your lungs at that point, assuming the pressure does not change?

Discuss how the hardness or softness of the landing surface is related to the time required to stop the egg

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.