What was Great Britain’s policy using African Americans during the war

What happens to the light rays when they hit the specimen?

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?

Acaterpillar tries to climb straight up a wall a meter high, but for every 2 cm up it climbs, it slides down 1 cm. eventually, it reaches the top. when it reaches the top, it does not pull itself over so it will slide down 1 cm. what is the total displacement traveled?