# Thread: relative motion of two moving objects

1. ## relative motion of two moving objects

I need the ans with relevant figure :

Problem ::
Two particles P and Q, are 30m apart with Q due north of P. Particle Q is moving at 5m/s in a direction 90 deg and P is moving at 7m/s in a direction 30 deg. Find

(a) the magnitude and direction of the velocity Of Q relative to P,
(b) the time taken for Q to be due east of P,to the nearest second.

2. Hello manik
Originally Posted by manik
I need the ans with relevant figure :

Problem ::
Two particles P and Q, are 30m apart with Q due north of P. Particle Q is moving at 5m/s in a direction 90 deg and P is moving at 7m/s in a direction 30 deg. Find

(a) the magnitude and direction of the velocity Of Q relative to P,
(b) the time taken for Q to be due east of P,to the nearest second.
Here's the diagram showing the velocities.

Use the Cosine Rule to find the magnitude of the velocity of Q relative to P.

Then find the component of this velocity in a North-South direction (indicated by the dotted line on the diagram).

From this you can work out the direction of this velocity, and how long it takes before Q is East of P.

Can you complete it now?

### two particles P and Q, are 30m apart with Q due north of P.Particle Q is moving at 5 m/s in a direction 90° and P is moving at 7m/s in a direction 30°.Find the magnitude and direction of the veloof Q relative to P

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