2-d force problems with newtons laws

Question

a child drags a 0.518 kg toy elephant across flat ground at constant speed, with a 5.23 N force at a 51.0° angle. What is the normal force acting on the toy? 

Answer 1

 

F_n = normal force = ?

 

m = 0.518 kg

 

g = 9.81 m/s²

 

T = 5.23 N

 

θ = 51.0° (I am assuming this angle is above the horizontal, which is not stated in the problem.)

 

Set up equilibrium of forces in the vertical direction.

 

Tsinθ + F_n = mg

 

F_n = mg - Tsinθ

 

F_n = (0.518 kg)(9.81 m/s²) - (5.23 N)sin(51.0°) ≅ 1.02 N