As part of a safety investigation, two 1600 kg cars traveling at 21 m/s are crashed into different barriers.

a) find the average force exerted on the car that hits a line of water barrels and takes 1.8 s to stop.
b) find the average force exerted on the car that hits a concrete barrier and takes 0.14 s to stop.

Apositive charge moves in the direction of an electric field. which of the following statements are true? check all that apply. check all that apply. 1.the potential energy associated with the charge decreases. 2. the electric field does positive work on the charge. 3. the electric field does negative work on the charge. 4. the potential energy associated with the charge increases. 5. the electric field does not do any work on the charge. 6. the amount of work done on the charge cannot be determined without additional information.

Anthropology is the study of the effects of disease on the body, while forensic anthropology studies the disease of crime a.) true b.) false

Ablock of mass m slides on a horizontal frictionless table with an initial speed v0 . it then compresses a spring of force constant k and is brought to rest. the acceleration of gravity is 9.8 m/s2 . how much is the spring compressed x from its natural length?