A child is in danger of drowning in the river. The river has a current of 2.5 km/hr . The child is 0.6 km from the shore. A rescue boat with speed 20.0 km/hr (with respect to the water) ,located 0.8km downstream, sets off from the shore.(adsbygoogle = window.adsbygoogle || []).push({});

What would be the optimum angle (shore -> boat ) to reach the child as fast as possible ?

And how long will it take to the boat to reach him?

I'm not sure if this is the correct way to draw this :

3. The attempt at a solution

a = 0.6 km

b = 0.8 km

v = 20.0km

u = 2.5km

c = √(a² + b²)

how do I find the angle?

I feel a little bit lost, your help is appriciated.

Thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Kinematics question using vectors

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**