A1050 kg automobile is at rest at a traffic signal. at the instant the light turns green, the automobile starts to move with a constant acceleration of 3.3 m/s2. at the same instant a 2350 kg truck, traveling at a constant speed of 8.6 m/s, overtakes and passes the automobile.
(a) how far is the center of mass of the automobile-truck system from the traffic light at t = 2.1 s?
(b) what is the speed of the center of mass of the automobile-truck system then?

Part a)

Part b)

Explanation:

As we know that initial velocity of the center of mass of the system of truck and car is

Here we know that

so we have

Similarly the acceleration of center of mass is given as

Now we know that the center of mass of the system will move a distance

Part b)

final speed of the center of mass is given as

radial fractures in a piece of glass look most like which of the following?

a. spokes of a wheel

b. a circle

c. a zig zag

d. none of the above

the correct answer is a. spokes of a wheel

hope this (: