Physics - Velocity - Displacement?

Question

Starting from home, you bicycle 20 km north in 2.9 h, then turn around and pedal straight home in 1.9 h.

What is your displacement at the end of the first 2.9 h?

= km (north)

What is your average velocity over the first 2.9 h?

= km/h (north)

What is your average velocity for the homeward leg of the trip?

= km/h (south)

What is your displacement for the entire trip?

= km (north)

What is your average velocity for the entire trip?

= km/h (north)

Answer 1

I bet your computer has a calculator that you can pull up onto your screen, right?

Can you divide 20 by 2.9?

Can you divide 20 by 1.9?

Can you add 2.9 to 1.9 and divide the sum into 40km?

etc.

Answer 2

What is your displacement at the end of the first 2.9 h?

= 20 km (north)

What is your average velocity over the first 2.9 h?

= 20/2.9 =~ 6.90 km/h (north)

What is your average velocity for the homeward leg of the trip?

= 20/1.9 =~ 10.53 km/h (south)

What is your displacement for the entire trip?

= 0 km (you end up where you started)

What is your average velocity for the entire trip?

= (20+20)/(2.9+1.9) =~ 8,33 km/h