In: Physics
20 km east plus 10 km northeast
Two vector addition:
Suppose given that Vector is R and it makes angle with +x-axis, then it's components are given by:
Rx = R*cos
Ry = R*sin
Using above rule: We need to add
20 km east + 10 km North east
A = 20 km east = 20 km at 0 deg from +x-axis
Ax = 20*cos 0 deg = 20 km
Ay = 20*sin 0 deg = 0 km
A = (20 i + 0 j) km
B = 10 km North-East = 10 km at 45 deg from +x-axis
Bx = 10*cos 45 deg = 7.07 km
By = 10*sin 45 deg = 7.07 km
B = (7.07 i + 7.07 j) km
Now Adding above two vectors
R = A + B = (20 i + 0 j) + (7.07 i + 7.07 j)
R = (20 + 7.07) i + (0 + 7.07) j
R = 27.07 i + 7.07 j
Magnitude of vector R will be:
|R| = sqrt (27.07^2 + 7.07^2) = 27.978 km = 28.0 km
Direction of vector R will be:
Direction = arctan (7.07/27.07) = 14.64 degree
So Vector R will be:
R = 28.0 km at 14.64 degree North of East