There are 4 questions Find 3u vector 4 v vector for u vecto

There are 4 questions

Find 3u vector - 4 v vector for u vector= i and v vector = - 12 i A Jet is flying through a wind that is blowing with a speed of 50 mph in the direction of N30 degree E (see figure). The jet has a speed of 775 mph relative to the air, and the pilot heads the jet in the direction N45 degree E. Find the true speed of the jet. (Round to the nearest integer.) Find the angle between the vectors u vector = i + i and v vector = i - i Find the component of u vector = (3, 0) along v vector = (8, 6). A car is on a driveway that is inclined 20 degree to the horizontal. If the car weighs 2800 lb, find the force required to keep it from rolling down the driveway. (Round to the nearest lb.)

Solution

28     u=i    v=-12j

3u - 4v= 3i -(-48j)= 3i+48j

30.     u= i + j      v= i - j

I u I= sqrt(1+1)=sqrt2

I v I= sqrt(1+1)= sqrt2

u.v= 1*1 + 1*-1=0

u.v= I u I I v I cos theta

0=2 cos theta

theta=pi/2