Question

如圖所示，邊長(zhǎng)為l的正方形區(qū)域abcd內(nèi)存在著勻強(qiáng)電場(chǎng)．質(zhì)量為m，電荷量為q的帶電粒子以速度v₀從a點(diǎn)進(jìn)入電場(chǎng)，恰好從c點(diǎn)離開電場(chǎng)，離開時(shí)速度為v，不計(jì)重力，求電場(chǎng)強(qiáng)度．                             

                                                                                                  

                                                                                                                                 

Answer 1

解：帶電粒子在勻強(qiáng)電場(chǎng)中只受電場(chǎng)力，電場(chǎng)力F=qE，

帶電粒子沿電場(chǎng)方向的位移等于l，

所以電場(chǎng)力做功W=Fl=qEl．

根據(jù)動(dòng)能定理W=△E_k

即qEl=

解得E=

答：該電場(chǎng)強(qiáng)度為．