Answer:
10 m/s
Explanation:
The problem can be solved by using the law of conservation of momentum: the initial momentum has to be equal to the final momentum, so we can write the following


where
is the mass of the first car
is the initial velocity of the first car
is the mass of the second car
is the initial velocity of the second car
is the final velocity of the two combined cars after the collision
Re-arranging the equation and substituting the numbers, we find

Answer:
9.72s
Explanation:

Here we need to find out the time that the car took to achieve the velocity of 70km/hr after starting from rest . Firstly convert the final velocity in m/s by multiplying it by 5/18 , as ,
- As we know that the rate of change of velocity is known as acceleration , so ;
Plug in the respective values ,
Simplify ,
Cross multiply ,
Simplify
<h3>Hence the required answer is 9.72s.</h3>
The centre of mass of the objects is (0,1)m .
What do you mean by Centre of mass?
The centre of mass is a position defined relative to an object or system of objects .
We have given
m1=2kg , y1= 3
m2= 3kg ,y2=2.5m
m3=2.5kg ,y3= 0m
m4=4kg , y4= -0.5m
Ycm=mixi/mi
→2×3+3×2.5+2.5×0+4×0.5/4.5
→1m
Centre of mass of these object is at (0,1)m .
to learn more about centre of mass click herehttps://brainly.com/question/19426784
#SPJ9