1. There is a famous intersection in Kuala Lumpur, Malaysia, where thousands of vehicles pass each hour. A 750 kg Tesla Model S traveling south crashes into a 1250 kg Ford F-150 traveling east. What are the initial speeds of each vehicle before collision if they stick together after crashing into each other and move at an angle of 320 and a common velocity of 18 m/s.

Solution :

Let the positive is along the East and the positive direction is along the north.

Given :

Mass of the Tesla car, =

Mass of the Ford car,

Now let the initial velocity of Tesla car in the south direction be =

The initial momentum of Tesla car,

Let the initial velocity of Ford car in the east direction be =

So the initial momentum of the Ford car is

Therefore, the initial velocity of both the cars is

Now the final velocity of both the cars is

So the vector form is :

Therefore the momentum after the accident is

According to the law of conservation of momentum, we know

From,

We get,

Therefore the speed of Tesla car before collision = 25.4 m/s

The speed of ford car before collision = 24.4 m/s

the doppler effect is used by weather forecasters to measure 

moving clouds