There are two forces on the 1.4 kg box in the overhead view of?

Question

but only one is shown. It also shows the acceleration of the box.
(a) Find the second force in unit-vector notation.
( N) i + ( N) j
(b) Find the second force as a magnitude and direction.
N, ° (counterclockwise from the +x-axis is positive)

Answer 1

It is difficult without a diagram. I am assuming that the block is accelerating in a Cartesian coordinate system at some angle le. I will assume that the direction of acceleration is some angle, th, above the x axis.

One force is acting on the block, with angle ph from the horizontal. The second force is unknown, but can be found using vectors. Let's set the angle of the second force as ni

In the x direction sum Fx=m*ai
In the y direction sum Fy=m*aj

Sum the forces in the x
F1*cos(ph)+F2*cos(ni)=
m*a*cos(le)

Isolate F2*cos(ni)
F2*cos(ni)=
m*a*cos(le)-F1*cos(ph)

Likewise, sum the forces in the y
F1*sin(ph)+F2*sin(ni)
=m*a*sin(le)

Isolate F2*sin(ni)
F2*sin(ni)=
m*a*sin(le)-F1*sin(ph)

now divide F2*sin(ni)/(F2*cos(ni))

Tan(ni)=
(m*a*sin(le)-F1*sin(ph))/
(m*a*cos(le)-F1*cos(ph))

solve for ni by taking ATAN of the number on the right

Given that, solve for F2 and check both equations.

j

Answer 2

there is no diagram reffered to by you.