Describing Motion

Describing Motion

Learning Targets

• i can calculate speed, average speed

• i can calculate time and distance from equation of speed

Open Ended

All matter in the universe is constantly in motion.

Take a moment to think about the above statement and describe an example of something in motion. Then, describe something that is in motion that we cannot see in motion. Respond with your thoughts.

Motion

• Motion is change in distance travelled by an object over time.

• to measure the motion of an object we measure speed

Moving Objects

Usually, we describe the motion of an object based on how fast an object is moving. What term would you use to describe how fast an ob object is moving?

Speed

• Speed is the distance traveled by an object divided by the time taken to travel that distance. Speed is measured in meters per second m/s.

• Speed is a quantity that describes how fast something is moving.

Calculating Speed

• To calculate an object's speed, you must know the total distance traveled and the time it took the object to travel that distance.

• You can can calculate an object's speed using the formula to the right.

• You may also see the formula written as s = d/t; where s = speed, d= distance, and t= time.

Average Speed

• Most objects do not move at a constant, unchanging speed.

• When using the formula to calculate speed, you are calculating the average speed of an object.

• In the example to the right, the car's average speed was 50 kilometers per hour. Sometimes, the car was moving slower, and at other times it was moving faster.

Open Ended

Practice Problem #1: Consider the following situation: A red car and a blue car both traveled 300 kilometers between Bakersville and Smithtown. The red car completed the trip in 4 hours. The blue car completed the trip in 3 hours. Calculate the speed of each car. Which car traveled faster? (Your answer should include the speed of each car and which car traveled fastest.)

Open Ended

Consider the following situation: A red car and a blue car both traveled 350 kilometers between dhaka and chattogram. The red car completed the trip in 4 hours. The blue car completed the trip in 3.5 hours.

Could you have known which car traveled faster without performing a calculation? Explain your response.

Open Ended

Consider the following situation: Student A and Student B both walked for 15 minutes. Student A walked 1 kilometer. Student B walked 2 kilometers.

Could you have known which person walked faster without performing a calculation? Explain your response.

Open Ended

A migrating bird can travel at a speed of 30 m/s. How far will it travel

in 25 minutes at this speed? Give your answer in metres (m), and in

kilometres (km).

Open Ended

A cargo ship travels at an average speed of 12 m/s. How long will it take to

travel between two ports which are 600 km apart?

Open Ended

A car travels from teknaf to tetulia. during the journey, it travels first 150 kilometres in 2 hours, next 100 km in 1.5 hrs, then it stops for refueling and lunch for 30 minutes, after that it travels 200 km in 2.5 hrs and last 150 km in 2 hrs. calculate the average speed of the car during the whole journey.