Question

A 70 Kg bike traveling at 5m/s north is hit by a 30 Kg scooter traveling 10m/s north. The bike and scooter stick together. What is their final velocity?

Answer 1

Explanation:

A 70 Kg bike traveling at 5m/s north is hit by a 30 Kg scooter traveling 10m/s north. The bike and scooter stick together. What is their final velocity?

4.5 Relative Motion in One and Two Dimensions | University Physics ...

Your velocity relative to the other train is 5 m/s west. ... A truck is shown traveling south at a speed V sub T E of 70 km/ ... (b) In what direction must the pilot head her plane to fly due north? ... Why doesn't he need to keep his eyes on the ball?

Answer 2

Answer:

→rPS=→rPS′+→rS′S.

The relative velocities are the time derivatives of the position vectors. Therefore,

→vPS=→vPS′+→vS′S.

The velocity of a particle relative to S is equal to its velocity relative toS′

plus the velocity ofS′

relative to S.

We can extend (Figure) to any number of reference frames. For particle P with velocities →vPA,→vPB,and→vPC

in frames A, B, and C,

→vPC=→vPA+→vAB+→vBC.

We can also see how the accelerations are related as observed in two reference frames by differentiating (Figure):

→aPS=→aPS′+→aS′S.

We see that if the velocity of S′

relative to S is a constant, then →aS′S=0

and

→aPS=→aPS′.

This says the acceleration of a particle is the same as measured by two observers moving at a constant velocity relative to each other.