The three forces (in units of N) given below are acting on a 20 kg mass. Calculate the magnitude of the acceleration of the mass. stack F subscript 1 with rightwards harpoon with barb upwards on top equals 3 i with hat on top space space space space space stack F subscript 2 with rightwards harpoon with barb upwards on top equals 5 j with hat on top space space space space stack F subscript 3 with rightwards harpoon with barb upwards on top equals open parentheses i with hat on top minus 3 j with hat on top close parentheses space space A. 0.2 m/s^2 B. 0.224 m/s^2 C. 0.1 m/s^2 D. 1.0 m/s^2

B. 0.224 m/s²

Explanation:

Given:

Mass of the object (m) = 20 kg

The forces acting on the object are:

Now, the net force acting on the object is equal to the vector sum of the forces acting on it. Therefore,

Now, the magnitude of the net force is equal to the square root of the sum of the squares of its components and is given as:

Now, from Newton's second law, the magnitude of acceleration is equal to the ratio of the magnitude of net force and mass. So,

Magnitude of acceleration is given as:

Therefore, option (B) is correct.

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle