Answer:
3 N to the right
Explanation:
There are two forces acting on the car:
- A force of 10 N towards the right
- A force of 7 N towards the left
Therefore, the net force is given by the difference between the two, since they are in opposite directions:

And the direction is to the right, since the force to the right has greater magnitude than the force to the left.
Explanation:
A) Use Hooke's law to find the spring constant.
F = kx
40 N = k (0.4 m)
k = 100 N/m
B) Period of a spring-mass system is:
T = 2π √(m / k)
T = 2π √(2.6 kg / 100 N/m)
T = 1 s
Frequency is the inverse of period.
f = 1 / T
f = 1 Hz
Explanation:
Displacement=Velocity×time
=24.7×16.00
=395.2m
Therefore the displacement within the time interval is 395.2m
In rivers that are close to sea
Answer: Please find the answer in the explanation
Explanation: According to the Newton 3rd law of motion which state that;
In every action, there will be equal and opposite reaction.
when the piston of a fountain pen with a nib is dipped into ink and and the air is released by pressing it, a force is applied which act on the molecules of the ink by pushing the molecules. When the force is released, there will be a reaction force by pulling the molecules of the ink into the pen. Thereby the ink fills in the pen.