Two cars approach each other; both cars are moving westward, one at 79 km/h, the other at 60 km/h. (a) what is the velocity of the first car relative to (in the reference frame of) the second car

Explanation:

Given that,

There are two cars say A and B. Both are approaching each other moving towards westward.

Speed of car A,

Speed of car B,

We need to find the velocity of the first car relative to (in the reference frame of) the second car. As both are moving in same direction, there relative velocity is given by :

v' = 19 km/h

So, the velocity of car A with respect to car B is 19 km/hr. Hence, this is the required solution.

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s