Explanation:
Given that,
Force, F = 70 N
Angle, [tex]\theta=50^{\circ}[/tex]
Acceleration of the boy, a = 1.8 m/s²
(a) Net force is equal to the product of mass and acceleration. So,
[tex]m=\dfrac{F}{a}\\\\m=\dfrac{70}{1.8}\\\\m=38.89\ kg[/tex]
(2) Normal force = upward force
So,
[tex]F=mg\cos\theta\\\\F=38.89\times 9.81\times \cos(50)\\F=245.23\ N[/tex]
Hence, mass is 38.89 kg and the normal force is 245.23 N.
