Velocity

Suppose you take a trip that covers 180 km and takes 3 hours to make. Your average speed is

60 km/h.

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

D: Instantaneous speed.

A unit of velocity is the meter. True or false

False

A van is traveling east at 15 km/hr passes a sports car going west at 35 km/hr. The speed of the sports car relative to the van is 20 km/hr.

False

Average speed is defined as the time it takes for a trip divided by the distance.

False

A pencil lies on your desk. If the Earth is moving around the sun at a speed of 30 km/s, how fast is the pencil moving relative to the desk? How fast is the pencil moving relative to the sun?

b. 0 km/s; 30 km/s

What is the average speed of a cheetah that runs 88 m in 5 seconds?

17.6 m/s

How far does a car travel if it is going at 30 m/s for 3 minutes? (Watch Units!)

If a car is traveling 30 m/s for 3 minutes then it will have traveled 5400 meters in those three minutes. 5400 m/s

Write a short paragraph explaining the difference between constant speed, average speed, instantaneous speed, and velocity. Make sure to give examples of all four.

The difference between constant speed, instantaneous speed, average speed, and velocity is well velocity is different from all of of them because velocity includes the direction an object is going and magnitude while speed includes just magnitude if you are going north that is your velocity. Average speed is different because it's the distance covered by the amount of time it took for that object to go that distance such as say you go 100 km in 3 hours your average speed was 33.3 km/hr. Constant speed is different because the speed never changes if you are going a constant speed you are always staying at that certain speed. Last but not least is instantaneous speed is different because it is the speed you are going at that exact moment of time an example of this would be if you are in the car and you look down at the speedometer and you see 65mph then you know that your instantaneous speed is 65mph.

The rate at which distance is covered is called speed.

True

Velocity is different from speed in that velocity is speed in a given direction.

True

Velocity tells you how fast an object is moving, while distance tells you how far an object has moved.

True

When we discuss the motion of something, its motion is described relative to something else.

True

Suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour (magical car). Which of the following is NOT true?

Your velocity is constant.

Speed is

a. a measure of how fast something is moving. b. always measured in terms of a unit of distance divided by a unit of time. c. the distance covered per unit time. Selected: d. all of the above.

One possible unit of speed is

a. miles per hour. b. light years per century. c. kilometers per hour. Selected: d. all of the above.