Question #8f4d7

1 Answer
Sep 13, 2016

Answer:

#55.8^@#, rounded to one decimal place.

Explanation:

Given two vectors
#vecS#, with #|vecS|=4# and #vecR#, with #|vecR|=6#
Let #theta# be the angle between the two.
By definition of dot product we have
#vecS cdot vecR=|vecS||vecR|cos theta#
Equating to the given value we get
#|vecS||vecR|cos theta=13.5#
#=>4xx6cos theta=13.5#
#=>cos theta=13.5/24=0.5625#
#=> theta=cos^-1 0.5625#
#=> theta=55.8^@#, rounded to one decimal place.