<span>Displacement is the difference between the initial position and the FINAL position of an object.
Hope this helps!</span>
Question:
A 63.0 kg sprinter starts a race with an acceleration of 4.20m/s square. What is the net external force on him? If the sprinter from the previous problem accelerates at that rate for 20m, and then maintains that velocity for the remainder for the 100-m dash, what will be his time for the race?
Answer:
Time for the race will be t = 9.26 s
Explanation:
Given data:
As the sprinter starts the race so initial velocity = v₁ = 0
Distance = s₁ = 20 m
Acceleration = a = 4.20 ms⁻²
Distance = s₂ = 100 m
We first need to find the final velocity (v₂) of sprinter at the end of the first 20 meters.
Using 3rd equation of motion
(v₂)² - (v₁)² = 2as₁ = 2(4.2)(20)
v₂ = 12.96 ms⁻¹
Time for 20 m distance = t₁ = (v₂ - v ₁)/a
t₁ = 12.96/4.2 = 3.09 s
He ran the rest of the race at this velocity (12.96 m/s). Since has had already covered 20 meters, he has to cover 80 meters more to complete the 100 meter dash. So the time required to cover the 80 meters will be
Time for 100 m distance = t₂ = s₂/v₂
t₂ = 80/12.96 = 6.17 s
Total time = T = t₁ + t₂ = 3.09 + 6.17 = 9.26 s
T = 9.26 s
1. By predicting the path of hurricanes, it is possible to warn people in its prospective path in advance. This way lives can be saved. In addition economic cost. associated with its destruction, can be minimized by bracing in advance for the storm along its path.
2. When the sea temperatures increase, there is increased vaporization of water into the atmosphere. This causes a transfer of heat into the atmosphere from the hydrosphere. This causes a drop of pressure in the local region that is one ingredient associated with the beginning of a hurricane.
3. The more the humidity, it means the more the heat transfer to the atmosphere through condensation. This reduces the pressure proportionally with the amount of humidity. This low pressure is an ingredient for hurricanes. In addition, the higher the humidity the larger the clouds and the larger the thunderstorms and precipitation associated with the hurricane
4. Winds drive hurricanes and determines their vicious force. In the formation of the hurricane, low winds are required to allow the formation of the funnel at the front betwen the cold and warm air masses. Winds blowing in congruence with the hurricane after then make it stronger while those that blow against it weaken it.
5. The answer is; YES, I would expect a hurricane. This is because at 12 0 N and 45 0 W are the open oceans of the Pacific. The average sea temperaturs in summer is between 15 0 and 20 0. At 27.5 0, this increases the humidity at the local region and therefore the tranfer of heat to the atmsphere. The light breeze gives the stability required for the air convection currents to occur forming a funnel front between the air masses.
All you have to do is get the culmative effect of the forces by predicting the direction in which each object will move. Just write down what you know and put down questions for your teacher.