Answer:
4. It is the force of the road on the tires (an external force) that stops the car.
Explanation:
If there is no friction between the road and the tires, the car won't stop.
You can see this, for example, when there is ice on the road. You can still apply the brakes (internal force), but since there is no friction (external force) the car won't stop.
The force of the brakes on the wheels is not what makes the car stop, it is the friction of the road against still tires that makes it stop.
Answer:
the displacement of the object is 5 units
Explanation:
The computation of the displacement of the object is shown below:
= Move to the right + move to the right - move to the left
= 6 units + 3 units - 4 units
= 9 units - 4 units
= 5 units
Hence, the displacement of the object is 5 units
Answer:
External force on him will be 112 N
Explanation:
We have given the mass of the sprinter m =70 kg
Acceleration of the sprinter 
We have to find the net external force
According to second law of motion force = mass ×acceleration
Force is dependent on the mass and acceleration
So 
So external force will be 112 N
A.The four lifestyle choices which I could change are:
1. The amount of physical exercise I engage in on a daily basis.
2, The number of hours I sleep.
3. The quantity of junk foods I consume daily and
4. Cultivation of the habit of spending time alone daily.
B. My days are always very busy, so I do not engage at all in physical exercise. Adding at least a thirty minute of physical exercise to my daily tasks will improve my health considerable. Due to the nature of my day, I usually eat on the move, thus I eat junk foods everyday. Eating healthy and balanced diet will go a long way in improving my health. I sleep for three hours only everyday, from 2 am to 5 am.This is because I have to leave my house very early in the morning and I don't usually get to sleep until 2 am in the morning. Spending more hours sleeping will improve my overall health. I want to start spending at least 30 minutes alone on a daily basis in order to meditate and to reflect over the events of the day. This will be a great boost to my mental health.
It's b, because the more force an object it is given the harder it will be for it to slow down.
