physics 2 & 3 quiz review

You toss a ball straight up in the air. At the highest point, the ball's

velocity is zero and the acceleration is downward.

You drop a bowling ball and a baseball from the same height and at the same time. The bowling ball will hit the ground first. (Neglect air friction)

false

An iron robot falls from rest at a great height. Neglecting air resistance, what distance has it fallen in the first 3.5 seconds?

60 m

If you drop a ball in the absence of air resistance, it accelerates downward at 9.8 m/s2. If instead you throw the ball upward, then its downward acceleration after release is

equal to 9.8 m/s2.

A bullet is fired straight down from a hovering helicopter. If we neglect air friction, then the velocity of the bullet

increases at 9.8 m/s each second.

Calculate the average speed (in m/s) of a cheetah that runs 140 meters in 5 seconds

28

A rifle bullet is fired horizontally at the same instant another bullet is allowed to drop from rest at the same height. Which bullet strikes the earth first?

Both strike at the same instant.

A football is thrown upward at some angle above the horizontal. If we neglect air friction, then we can conclude that the acceleration vector of the football is

down

(Ignore air friction for this problem.) Two identical balls are thrown simultaneously from the top of a very tall cliff. Ball A is thrown downward with an initial velocity of 6 m/s, while ball B is thrown straight upward with an initial velocity of 9.8 m/s. After one second has elapsed, the

velocity of ball B is zero.

Neglecting friction, if a Cadillac and Volkswagen start rolling down a hill together, the heavier Cadillac will get to the bottom

at the same time as the Volkswagen.

An iron robot falls from rest at a great height. Neglecting air resistance, what is its speed after it has fallen for 3.5 seconds?

34.4 m/s

A person standing at the edge of a cliff throws one rock straight up and another rock straight down at the same initial speed. The rock that was thrown __________ has less speed at impact.

Actually, each rock has the same speed just before impact.

In order to find the depth of a well, you drop a stone into it and time its fall. It hits the water after falling for 1.5 s. The depth of the well is about

11 m

Suppose you throw a ball vertically downward with a speed of 10 m/s. Neglecting air friction, what would be the speed of the ball one second later?

19.8 m/s

Calculate the acceleration of a car (in km/h*s) that can go from rest to 100 km/h in 10 s.

10

Acceleration represents the

change in velocity with respect to time

In the case of uniform accelerated motion, the graph of velocity versus time is linear (a straight line).

true

The Flash (a superhero) runs 10,000 meters in 3 seconds. What is the Flash's velocity?

3333 m/s

Velocity is

a vector quantity

Average speed is calculated by

dividing the distance traveled by the elapsed time

A car at rest begins to accelerate to a velocity of 20 m/s in a time of 5 seconds. Find the car's acceleration.

4 m/s^2

If the acceleration is zero, the velocity is constant

true

The slope of the distance traveled versus time graph is the

velocity

speed is

a scalar quantity

In the case of uniform accelerated motion, the graph of distance traveled versus time is linear (a straight line).

true

The slope of the velocity versus time graph is the

acceleration