To calcculate the braking force of the car moving, we use Newton's second law of motion which relates the acceleration and the force of an object moving. The force of an object moving is directly proportional to its acceleration and the proportionality constant is the mass of the object. It is expressed as:

Force = ma

Acceleration is the rate of change of the velocity of a moving object. We calculate acceleration from the velocity and the time given above.

a = (10 m/s) / 5 s = 2 m/s^2

So,

Force = ma

Force = 1000 kg ( 2 m/s^2 )

**Force = 2000 kg m/s^2 or 2000 N**

**Answer:**

the motion that repeat itself in equal interval of time is called periodic motion and it is equal to harmonic motion. for example pendulum

**Answer:**

7 Electrons

**Explanation:**

Assuming that final energy level is that same as valence shell, we first need to find how many of the electrics will be used to fill the ones before it.

Electron shell capacities are as follows :

First shell/Ebergy level: 2 electrons

Seconds shell/energy level : 8 electrons

Third shell /energy level :8 electrons

The first two shells total to 10, and the first three shells total to 18. Since chlorine (17) fills more than 2 shells but less that 3, the third one is its final energy level. We find the number in the final energy level by subtracting the 10 in the full first two. 2+8=10

17-10=7

Chlorine has 7 electrons on its final energy level.

Hope this helped!

**Answer:**

**Explanation:**

The velocity of the fish relative to the water when it hits the water is given by its magnitude and its angle:

The horizontal speed () of the fish is constant, while vertically we have a free fall (), using the kinematic equations we can calculate the vertical speed ():

Now, we calculate the velocity of the fish:

**Answer:Convection **

**Explanation:**

Convection is the heat transfer procedure by the movement of liquid or gas molecules. It is a combination of diffusion and bulk motion of molecules. Near the surface of the liquid diffusion process dominates while at certain height bulk motion of liquid dominates.

Convection can be

Natural : Natural convection occurs due to density differences

Forced: Force convection occurs when we apply external heat source.