-- The overall <em>distance</em> he travels is (100m + 30m + 70m) = <em>200 meters</em>.
-- His <em>displacement </em>when he arrives at his front door is
D = (100m East) + (30m West) + (70m East)
D = (100m + 70m)East + (30m)West
D = (170m East) + (30m West)
<em>D = 140 meters East </em>
It's interesting to notice that his displacement is 60 meters shorter than the distance he walked.
That's because there's a stretch of 30 meters somewhere in the middle that he actually covered <em>three times</em>.
Two of those times added to the distance his shoes covered (2x30m=60m), but they cancelled out of the displacement.
His front door is 140 meters East of school. He walked 60m farther than that, going back and forth over the 30m piece.
Qs 1: m = 1/2*KE*V^2
qs 2: 6,223.39 kg
Relative age is the age of a rock layer (or the fossils it contains) compared to other layers. It can be determined by looking at the position of rock layers. Absolute age is the numeric age of a layer of rocks or fossils. Absolute age can be determined by using radiometric dating.
Density because it can measured and felt.
Answer:
(a)When ignoring air resistance its accelerating increases steadily .
(b)When considering air resistance then its acceleration decreases this could either be uniformly or unevenly.
Hope this helped.
