1) In a circular motion, the angular displacement

is given by

where S is the arc length and r is the radius. The problem says that the truck drove for 2600 m, so this corresponds to the total arc length covered by the tire:

. Using the information about the radius,

, we find the total angular displacement:

2) If we put larger tires, with radius

, the angular displacement will be smaller. We can see this by using the same formula. In fact, this time we have:
Kinetic energy=1/2mv^2
=1/2(142*10^-3)(42.9)^2=130.6=131J
Explanation:
average speed = total distance travelled / total time travelled
time to travel the first 6km: 6 / 50 = 3/25 (h)
time to travel the next 6km: 6 / 90 = 1/15 (h)
[I think there's problem in the question 'cause 900km/h sounds impossible for normal person to travel in normal condition]
The total time: 3/25 + 1/15 = 14/75 (h)
Average speed over the 12 km drive will be:

Answer:
A: used has four times the tensile strength of steel and the timber frame, incorporating
Explanation:
Option A is correct because it conveys the correct message intended by the statement and has no grammatical errors.
Option B is wrong because to say "has four times the tensile strength of steel has" is just grammatically and idiomatically wrong as has is used twice in the sentence.
Option C is wrong because the statement that has to do with the flexibility of the timber's frame is more like a separate fact and does not fall under the scope of trying to further explain a fact.
Option D is wrong because it has the same problem in Option C. The comma that is placed after "steel" breaks the sentence and hence does not provide a good understanding of why the building can withstand earthquakes.
Option E is grammatically wrong for using does in the sentence "has four times the tensile strength steel does"
False! Because the acid rain it becomes a chemicals it does not air get into the rain and up the acidity levels.
Hope it helped you.
-Charlie
:)