Step-by-step explanation:
Given that,
Mass of a puck, m = 8 kg
Initial velocity, u = 10i m/s
Final velocity, v = (10i+12j) m/s
Time, t = 8 s
(a) Force acting on an object is given by the product of mass and acceleration.
F = ma
a is acceleration
![F=(m(v-u))/(t)\\\\F=(8* (10i+12j-10i))/(8)\\\\F=12j\ \text{N}](https://img.qammunity.org/2021/formulas/physics/college/7apharkvj3j6gsxoy9d0amfc9q4pac54ku.png)
(b) The magnitude of force is given by :
![F=√(12^2+0^2) \\\\F=12\ N](https://img.qammunity.org/2021/formulas/physics/college/2xw8gdddro24gpf0yyra3kduwsn6waak1c.png)
Hence, the component of force is 12j N and its magnitude is 12 N.