7. Three students traveled from Charlotte, NC to Anderson, SC. Ollie traveled by bus at 68mph south. Aggie traveled by train at 45 km/hour. Pete
flew at 310 mph. Which of the students represents a velocity? *
A. Ollie; He was on the ground and traveled in the units of mph.
B. Aggie; She traveled in units that were metric.
C. Pete: He flew and got there the fastest.
D. Ollie; It includes a direction.

An object is 10 cm from the mirror, its height is 1 cm and the focal length is 5 cm. what is the image height? (indicate the object orientation by including the + or - sign with the answer.) hi = cm +1 -1 +10 -10

Which is not an example of how an object gains elastic potential energy by stretching? a. jumping on a pogo stick b. pulling on a rubber band c. jumping on a trampoline

Cyclotrons are widely used in nuclear medicine for producing short-lived radioactive isotopes. these cyclotrons typically accelerate h- (the hydride ion, which has one proton and two electrons) to an energy of 5 mev to 20 mev. this ion has a mass very close to that of a proton because the electron mass is negligible—about 1 2000 of the proton’s mass. a typical magnetic field in such cyclotrons is 1.9 t. (a) what is the speed of a 5.0-mev h-? (b) if the h- has energy 5.0 mev and b = 1.9 t, what is the radius of this ion’s circular orbit?