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
Answer:
342 m/s
Explanation:
The velocity of sound in air is approximated as:
v ≈ 331.4 + 0.6 T
where v is the velocity in m/s and T is the temperature in Celsius.
At T = 18:
v ≈ 331.4 + 0.6 (18)
v ≈ 342.2
The velocity is approximately 342 m/s.
The presence of potential energy between particles supports the shape of a heating curve.
<h2>Potential energy and heating curve</h2>
The existence of potential energy between particles supports the shape of a heating curve because potential energy causes the heating curve flat as well as in curve form. The heating curves show how the temperature changes as a substance is heated up.
The potential energy of the molecules will increase anytime energy is being supplied to the system but the temperature is not increasing so when the heating curve go flat it means there is potential energy so we can conclude that the existence of potential energy between particles supports the shape of a heating curve.
Learn more about heating curve here: brainly.com/question/11991469
Learn more: brainly.com/question/26153233
The historical method includes what steps?
A balanced force is upon it because balanced means both sides are equal so they cancel each other out, while unbalanced means one side is weaker/stronger than the other and in this case its in a state of rest so the net force would be equal/balanced.