The answer of this is C!!!
Explanation:
∆x=300 m×2
∆t=1.5 s
v=∆x/∆t → v=2×300/1.5 = 400 m/s
Answer:
50 J
Explanation:
The net force acting on the box is given by the algebraic sum of the two forces, so:

The net work done on the box is equal to (assuming the net force is parallel to the displacement of the object)

where
F = 5 N is the net force on the object
d = 10 m is the displacement of the object
Substituting,

Answer:
70 kg is the mass of the object
Explanation:
This question can be solved with this simple formula:
Weight force = mass . gravity
686 N = mass . 9.8 m/s²
686 N / 9.8 m/s² = mass → 70 kg
Note → 1N = 1 kg . m / s²