CIE A Level Physics复习笔记5.1.5 Derivation of P = Fv
Derivation of P = Fv
- Moving power is defined by the equation:
- This equation is only relevant where a constant force moves a body at constant velocity. Power is required in order to produce an acceleration
- The force must be applied in the same direction as the velocity
Derivation
- The derivation for this equation is shown below:
Derivation of P = F × v
Worked Example
A lorry moves up a road that is inclined at 14.5° to the horizontal.
The lorry has mass 3500 kg and is travelling at a constant speed of 9.4 m s-1. The force due to air resistance is negligible.Calculate the useful power from the engine to move the lorry up the road.
Exam Tip
The force represented in exam questions will often be a drag force. Whilst this is in the opposite direction to its velocity, remember the force needed to calculate the power is equal to (or above) this drag force to overcome it therefore you equate it to that value.
转载自savemyexams
以上就是关于【CIE A Level Physics复习笔记5.1.5 Derivation of P = Fv】的解答，如需了解学校/赛事/课程动态，可至翰林教育官网获取更多信息。
往期文章阅读推荐：
全网破防！ALevel CIE数学M1疑似错题？经济P2难度飙升？5月6日大考考情分析必看！
A-Level CIE就大规模泄题发布最严处罚！哪些考生必须重考？你的成绩怎么办？
翰林AMC8视频课重磅上线！
国际竞赛真题资源免费领取
