As in an element?
He/ Helium
Answer:
1 km / 15min
Explanation:
The average speed is calculated by simply doing space divided by time so:
2km / 30min that becomes 1km / 15min
Have a good day.
Mac and Keena are experimenting with pulses on a rope. Mac vibrates one end up and down while Keena holds the other end. This creates a pulse which they observe moving from end to end. How does the position of a point on the rope before the start of the pulse compare to its position after the pulse passes? Explain your reasoning.
Answer:
The boat speed relative to the riverbank is 2.96 m/s
Explanation:
The boat move to the north at 2.7 m/s across the river and the river current is 1.2 m/s to the west, therefore the direction of the boat is perpendicular to the river (90).
The boat speed vb = 2.7 m/s
The current speed vc = 1.2 m/s
The formula to calculate the speed of the boad relative to the riverbanks (Vbc), as follow
vbc =
=
since cos 90 = 0, hence
vbc =
= 2.96 m/s