Linear Motion review

What is the acceleration of a car that maintains a constant velocity of 100km/h for 10s?

0km/h

What is the acceleration of a car moving along a straight road that increases its speed from 0 to 100km/h in 10s?

10km/h-s

Phil leans over the edge of a cliff and throws a rock upward at 5 m/s. How far below the level from which it was thrown is the rock 2 seconds later?

10m

While you are in a bus that moves at 100 km/h you walk from the back to the front at 10 km/h. What is your speed relative to the road outside?

110 km/h

How far does a horse travel if it gallops at an average speed of 25 km/h for 30 min?

12.5 km

Jogging Jake runs at 4 m/s along a train flatcar that moves at 10 m/s in the same direction. Jake's speed relative to the ground is

14m/s

The time it takes a car to attain a speed of 30 m/s when accelerating from rest at 2 m/s^2 is

15s

A pot that falls from a ledge and hits the ground 45 m below hits the ground at

30 m/s

What is the acceleration of a car that starts from rest and 5 seconds later reaches a speed of 20m/s?

4 m/s^2

Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration?

4.0 m/s^2

A car's speed 3 seconds after accelerating from rest at 2 m/s^2 is

6m/s

What exactly is meant by a "freely falling" object?

An object in free fall under gravity alone with no friction

When the distance fallen for a freely object 1 s after being dropped from a rest position? What is the distance for a 4-s drop?

It falls 5 m in 1s and 80m in 4s

If a car is moving at 90 km/h and it rounds a corner, also at 90 km/h, does it maintain a constant speed? A constant velocity?

It maintains a constant speed, but does not maintain a constant velocity.

How does Newton's first law of motion relate to Galileo's concert of inertia?

Newton refined Galileo's concept of inertia and made it his first law of motion

What relationship did Galileo discover about a ball's acceleration and the steepness of an incline? What acceleration occurs when the plane is vertical?

The steeper the incline, the greater the acceleration. On a vertical incline, the ball is in free fall.

What is the main difference between speed and velocity?

Velocity includes a direction, but speed does not.

What did Galileo discover in his legendary experiment on the Leaning Tower of Pisa?

a heavier stone does not fall significantly faster then a lighter one

Galileo discovered that when air resistance can be neglected, all objects fall with the same ______.

acceleration

A vehicle undergoes acceleration when it

all of the above

If an object moves with constant velocity, it's velocity must

change by the same amount each second

What type of path does a moving object follow in the absence of a force?

continues to move in straight line at a constant speed

What two units of measurement are necessary for describing speed?

distance/time

What did Galileo discover about moving bodies and force in his experiments with inclined planes?

in the absence of a retarding force, a body will keep moving at a constant speed in a straight line forever

What kind of speed is registered by an automobile speedometer?

instantaneous speed

A bird sitting on the limb of a tree is moving about 30 km/s with respect to the Sun. If the bird takes 1 second to drop down to a worm below, the worm would be 30 km downrange from the bird when it reached the ground. This faulty reasoning is best countered with Newton's

law of inertia

A gymnast performing somersaults in a high-flying plane moving at constant velocity needs to make

no adjustments

Which of the following is not a vector quantity?

speed

A ball rolling down an inclined plane each second picks up

the same amount of speed each second

A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before striking the water

the same for each bullet

What is Inertia?

the tendency of a body to maintains its state of motion in the absence of applied forces

Galileo's definition of speed was a breakthrough because he is acknowledged to be the first to consider ______.

time