Chapter 3 (Physics)

3. Suppose a car is moving in a straight line and its speed is increasing. If the car goes from 35 km/h to 40 km/h in the first second, and from 40 km/h to 45 km/h in the next second, what is the car's acceleration?

5 km/h/s

10. What does 10 m/s2 mean?

An object's speed changes 10 m/s every second.

4. What formula is correct?

speed = distance/time

5. Which has the greater average speed: a cheetah which sprints 60 yd in 3 s, or a leopard which sprints 90 yd in 6 s?

the cheetah

2. When you look at the speedometer in a moving car, you can see the car's:

instantaneous speed

9. The distance that a falling object travels:

is directly proportional to the square of time that the object falls.

6. An object is dropped from a tall building. At one instant it is traveling -30 m/s. Exactly one second later its speed is expected to be:

-40 m/s

8. An object is thrown downward. At one instant after its release it is traveling -30 m/s (downward). Exactly one second later its speed is:

-40 m/s

7. An object is thrown up in the air. At one instant after its release it is traveling 30 m/s upward. Exactly one second later its speed is:

20 m/s

1. Speed is...

~a measure of how fast something is moving ~the distance covered in a unit of time ~always measured in terms of a unit of distance divided by a unit of time