Icould really use some with these 4 problems. any will be greatly appreciated!

(7) is the same problem with different numbers as (4) in another question you posted: link

(8) is not correct.

(9) is not correct. The direction of the vector is where

so the applied force is the vector

(if you're not sure how to compute the (co)sine of the inverse-tangent expression, note that a tangent of 3/4 corresponds to a right triangle with hypotenuse 5)

The object is moved 7 ft in the same direction as , so that its displacement is given by the vector

Then the work done on the object is the dot product of these two vectors,

(the discrepancy here might be coming from finding a numerical value for )

(10) is correct. We can find a unit vector pointing in the direction of any vector by dividing by its magnitude:

146%

step-by-step explanation: