A car is traveling on an interstate highway. Can the car have a negative velocity and a positive acceleration? Can the car’s velocity change signs while it is traveling with a constant acceleration?

Using software, a simulation of a javelin being thrown both on earth and on the moon is created. in both cases, the velocity and angle of projection are kept the same. on earth, the javelin covers a distance y. what distance would it cover on the moon? (the moon’s gravity is about 1/6th that of earth.) a. 6y b. 6/y c. y/6 d. (y+6)2

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.