Answer: Kinetic frictional force = 23.76N
Explanation: Please see the attachments below
Given :
Vector A has a magnitude of 63 units and points west, while vector B has the same magnitude and points due south.
To Find :
The magnitude and direction of
a) A + B .
b) A - B.
Solution :
Let , direction in north is given by +j and east is given by +i .
So ,
and 
Now , A + B is given by :


Direction of A+B is 45° north of west .
Also , for A-B :


Direction of A-B is 45° south of west .
( When two vector of same magnitude which are perpendicular to each other are added or subtracted the resultant is always 45° from each of them)
Hence , this is the required solution .
Answer:
4. The choose b. 0.000355
Ans; 3.55× 10-⁴ = 0.000355
5. The choose C. 80600
Ans; 8.06 ×10⁴= 806×10² = 80600
I hope I helped you^_^
Answer:
mass is lifted 1.8 m. What is the potential energy of the mass 4. A 100 kg