Posted by **melissa** on Tuesday, January 1, 2008 at 8:12pm.

a boat that travels at a speed of 6.75 m/s in still water is to go directly across a river and back . the current flows at 0.50 m/s (a) at what angle(s) must the boat be steered. (b)How long does it take to make a round trip? (assume that the boats speed is constant at all times and neglect turn around time)

- physics -
**bobpursley**, Tuesday, January 1, 2008 at 9:05pm
If it is to go directly across,then it must be headed upstream.

Theta=arcsin(.5/6.75)

Then velocity across= 6.75*arccosTheta

If you need more assistance, ask a followup question.

- physics -
**Damon**, Tuesday, January 1, 2008 at 9:12pm
say the boat travels at angle T from straight across. Then the upstream component of the boat velocity relative to water must be .5 m/s to counteract current

so 6.75 sin T = .5 m/s

sin T = .5/6.75 = .0741

so T = sin^-1 (.0741) = 4.25 degrees from straight across toward upstream both ways.

The component of velocity across the river is then

6.75 cos 4.25 deg = 6.73 m/s

You did not say how wide the river is so I will call it D

time = 2 D/6.73

## Answer this Question

## Related Questions

- physics - A boat that travels at a speed of 6.75 m/s in still water is to go ...
- physics - A boat’s speed in still water is vBW = 1.85 m/s. If the boat is to ...
- trig/ vectors - Points C and D are directly across from each other on opposite ...
- Physics - A boat propelled so as to travel with a speed of 0.5m/s in still water...
- physics - A boat propelled so as to travel with a speed of 0.50m/s in still ...
- Physics - A boater wants to head straight across a river that has a current of ...
- math - The speed of a powerboat in still water is 35 mi/h. It is traveling on a ...
- Physics - A current of a river flows steadily from west to east at 1.00 m/s. A ...
- math - 20. Miguel is driving his motorboat across a river. The speed of the boat...
- physics - A motor boat whose speed is 2.6 m/s in still water, needs to point ...