Newton's 2nd Law Based Question

Question

A 1.81-kg drone is flying over a lake. With both the x and y directions horizontal (that is, viewing the drone from above), the drone's velocity changes from (3.91 m/s)i + (0.00 m/s)j to (9.67 m/s)i + (3.32 m/s)j in 6.36 s.

a) What is the x component of the net force, in N?

b) What is the y component of the net force, in N?

c) What is the magnitude of the net force, in N?.

Answer 1

The important equation here is F = m a, where F is the force, m is the mass, and a is acceleration.

We assume that the force in question is constant (which means that the velocity-depending air resistance is negligible).

The components of the force can be found using the same equation as follows

a) F_x = m a_x = m Δv_x / Δt = 1.81 kg × (9.67 m/s - 3.91 m/s) / 6.36 s = 1.64 N or in vector form (1.64 N)i

b) F_y = m a_y = m Δv_y / Δt = 1.81 kg × (3.32 m/s - 0.00 m/s) / 6.36 s = 0.945 N or in vector form (0.945 N)j

c) Assuming that the vertical component of the net force F_z = 0, the magnitude of the net force is given by

| F_net | = √(F_x² + F_y²) = √(1.64 N)² + (0.945 N)²) = 1.91 N