Highway safety engineers want to design roadside barriers that will crumple in the event that a car drives off the road and collides with them, slowing
down the car more gradually. The average person has a mass of 68 kg and
travels on a highway at a velocity of 27 m/s. If the engineers know that the
maximum force that a person can safely withstand is 2180 N, approximately
how much time is required to crumple the barrier to safely slow the person
with this force?

Which of the following quantities are units of momentum? (there could be more than one correct choice.) a)n m b) kg s/m c) kg m/'s d)n-s 12 points] e) kg m2/s2

Which type of bond is found between the atoms of a molecule? a. metallic b. delocalized electron c. covalent d. ionic

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)