I'm not sure if I am right on these questions please help

When should you express a vector along the x-axis as a negative vector?
(Points : 1)
when its magnitude is less than 1

when the arrow representing the vector would point toward negative x <--

when the arrow representing the vector would point toward positive x

when its magnitude is greater than 1

A boat in a river is moving forward at 10.0 km/h relative to the water with its front end pointed perpendicular to the flow of water. The water in the river is flowing at 3.00 km/h. What is the speed of the boat relative to the river bottom?
(Points : 1)
7.0 km/h

10.0 km/h

10.4 km/h <--

11.5 km/h

13.0 km/h

I'm right you're welcome

when the arrow representing the vector would point toward negative x <--

10.4 km/h <--

To answer the first question, you need to understand the concept of vector direction and the x-axis. In this case, if a vector is expressed along the x-axis as a negative vector, it means that the arrow representing the vector would point toward negative x. Therefore, the correct answer is "when the arrow representing the vector would point toward negative x."

To answer the second question, you need to consider the boat's velocity relative to the water and the velocity of the water itself. The boat's velocity relative to the water is given as 10.0 km/h, and the water's velocity is given as 3.00 km/h. Since the boat's front end is pointed perpendicular to the flow of water, the speed of the boat relative to the river bottom can be found using the Pythagorean theorem.

You can calculate it as follows:
- The boat's velocity relative to the river bottom is the square root of the sum of the squares of the boat's velocity relative to the water and the water's velocity.
- Substituting the given values, we get the square root of (10.0 km/h)^2 + (3.00 km/h)^2 = square root of (100 km^2/h^2 + 9 km^2/h^2) = square root of (109 km^2/h^2) ≈ 10.4 km/h.

Therefore, the correct answer is "10.4 km/h."