A student accurately uses the method for combining vectors. The two vectors she combines have magnitudes of 55 and 25 units. The answer that she gets is either 85, 20, or 55. Pick the correct answer, and explain.
it has to be within 55+-25
20
To combine vectors, you need to use vector addition. Vector addition involves adding the magnitudes of the vectors and considering their directions. In this case, we have two vectors with magnitudes of 55 and 25 units.
To find the resultant vector, you must add these magnitudes together, resulting in 55 + 25 = 80 units. Therefore, 85 is not the correct answer.
The magnitude of the resultant vector is obtained by finding the length of a straight line connecting the initial and final points of the vectors. It cannot be less than the magnitude of either of the individual vectors. Therefore, 20 is not the correct answer.
As for 55, it matches the magnitude of one of the vectors. However, it is not the correct answer for the resultant vector in this case. The magnitude of the resultant vector is 80 units, as calculated earlier.
Therefore, the correct answer is that the student obtained a resultant vector with a magnitude of 80 units.