Exam 2: Motion in One Dimension

It is not physically possible for the "position versus time" graph of a moving animal to be either perfectly vertical or perfectly horizontal.

Two identical stones are dropped from a tall building,one after the other.Assume air resistance is negligible.While both stones are falling,what will happen to the vertical distance between them?

If the "velocity versus time" graph of an object is a horizontal line,that object cannot be accelerating.

If an object stops moving at a point,then its acceleration must be zero at that point.

The plot below shows the position of an object as a function of time.The letters H-L represent particular moments of time.At which moment in time is the speed of the object the highest?

A child standing on a bridge throws a rock straight down.The rock leaves the child's hand at t = 0.Which of the graphs shown here best represents the velocity of the stone as a function of time?

A car accelerates from 5.0 m/s to 21 m/s at a rate of 3.0 m/s².How far does it travel while accelerating?

Which of the following situations is impossible?

A car is travelling north at 17.7 m/s.After 12 s its velocity is 14.1 m/s in the same direction.Find the magnitude and direction of the car's average acceleration.

A sports car can go from rest to 32 m/s in 3.88 s.The same car can come to a full stop from that speed in 3.96 s.What is the ratio of starting to stopping accelerations?

A ball is thrown straight upward with a velocity of 39 m/s.How much time passes before the ball strikes the ground? (Disregard air resistance. )

A person in a car is driving down a straight road.The instantaneous acceleration is decreasing with time,but is directed in the direction of the car's motion.The speed of the car is

A car moving at a velocity of 20 m/s is behind a truck moving at a constant velocity of 18 m/s.When the car is 50 m behind the front of the truck,the car accelerates uniformly at 1.8 m/s2.The car continues at the same acceleration until it reaches a velocity of 25 m/s,which is the legal speed limit.The car then continues at a constant velocity of 25 m/s,until it passes the front of the truck.The distance the car travels while accelerating,in meters,is closest to:

A stone is thrown vertically upwards,reaches a highest point,and returns to the ground.When the stone is at the top of its path,its acceleration

A ball is projected upward at time t = 0.0 s,from a point on a roof 90 m above the ground.The ball rises,then falls and strikes the ground.The initial velocity of the ball is 80.5 m/s.Consider all quantities as positive in the upward direction.The velocity of the ball when it is 89 m above the ground is closest to:

The equation vfs² = vis²+ 2a_s Δx applies to motion for which the "velocity versus time" graph is a straight line.

A toy rocket is launched vertically from ground level (y = 0 m),at time t = 0.0 s.The rocket engine provides constant upward acceleration during the burn phase.At the instant of engine burnout,the rocket has risen to 81 m and acquired a velocity of 40 m/s.The rocket continues to rise in unpowered flight,reaches maximum height,and falls back to the ground.The upward acceleration of the rocket during the burn phase is closest to:

A 8.7 hour trip is made at an average speed of 73.0 km/hr.If the first third of the trip (chronologically)was driven at 96.5 km/hr,what was the average speed for the rest of the journey?

An object is dropped from rest into a pit,and accelerates due to gravity at roughly 10 m/s2.It hits the ground in 5 seconds.A rock is then dropped from rest into a second pit,and hits the ground in 10 seconds.How much deeper is the second pit,compared to the first pit? Neglect air resistance.

If the fastest you can safely drive is 65 mi/h,what is the longest time you can stop for dinner if you must travel 541 mi in 9.6 h total?