HirdNG DAN QUAN Ll, suf DUNG II «? « TIEN HANH THI NGHIEN COC NUOC DE ION NGUOC v^'''''''' k'''' Pham Dinh Ci/ong 1 Muc dich Cbo hgc sinh (HS) thay dugc cd the de cdc cd nude Ign ngugc trong khong khi 2 Dung c[.]
HirdNG DAN QUAN Ll, suf DUNG «? II « TIEN HANH THI NGHIEN COC NUOC DE ION NGUOC v^'' k' Muc dich: Cbo hgc sinh (HS) thay dugc cd the de cdc cd nude Ign ngugc khong Dung cu: Mgt coc nhua hoac thiiy tinh suot, khong mau, mieng phang va nhan Mgt tam nhua cimg, phang, day 0,5mm (hoac td bia khong tham nudc) c6 kich thudc ldn ban mieng coc mgt cbiit Mgt chau hoac khay de nudc Tien hanh thi nghiem: Do nudc chiem 2/3 coc hoac day coc Dat tam nhua (hoac bia) len mieng coc - Dat mgt ban tay de len tam nhua (hoac bia) tren mieng coc ay tay cam coc Ign ngugc (thuc bien viec tren chau hoac khay rgng de hiing cac gigt nude rai xuong, tay dat len td bia phai kho) Tu tu bd tay giu td bia (hinh 1) HI Cau hoi goi md: Khi bo ban tay giu tam nhua (hoac bia) tai tam nhua (hoSc bia) dat d mieng Pham Dinh Ci/ong COC van dinh d mat coc chu khong rai xuong? Tai nudc coc bi Ign ngugc khong chay xuong? Tai ban tay giu tam nhua (hoac bia) phai kho? Neu ban tay udt thi xay hien tugng gi? - Khi quay coc xuong, ta c6 the de coc d tu the nghieng roi bo tay giu tam nhua (hoac bia) dugc khong? C6 the de coc Ign ngugc nhu tren ma coc de cac chat long khac (nude uong c6 gas, nude n6ng, rugu, dau an ) hay khong? Neu dat td bia len mieng coc, tai phai diing td bia khong tham nude? Giai thich: Trudng hgp nudc day coc (trong coc khong co bgt khi): Trong coc khong c6 khong nen khong co ap suat quyen, ap suat quyen nen vao tam nhua (hoac bia) dat d mieng coc nen nudc coc khong rai xuong dugc Trudng hgp nudc khong day coc: Khi coc dang d tu the nghieng luc dang Ign ngugc coc thi mgt so gigt nude coc rai xuong (vi lire tay ta nen vao tam nhua); ta bo tay giQ tam nhua (hoac bia) tbi tam nhua (hoac bia) dan boi phang ra, the tich khong coc tang nen ap suat khong coc giam Ap suat quyen ben ngoai Idn ban nen giQ tam nhua (hoac bia) chat vao mat coc Trudng hgp nude khong day coc nhung tay ta ep nhe deu len tam bia (hoac giay), nhung dam bao cho tam bia (hoac giay) van sat vdi mep coc, iip ngugc coc xuong ma khong c6 gigt nudc nao chay khoi coc tbi buong tay giu' tam bia (hoac giay) thi tam bia (hoac giay) se rai xuong va nude chay xuong het Nguyen nhan vi ap suat khong coc van bang ap suat quyen ben ngoai, ap suat ciia nudc coc se lam tam bia (hoac giay) rai xuong Tay ep tam nhua (hoac bia) vao coc phai that kho Neu tay udt thi nudc dinh giua tay va tam nhua (hoac bia) sinh luc keo tam nhua (hoac bia) xuong va nudc se chay khoi coc Trong Ign ngugc coc, coc dang d tu the nghieng neu ta bo tay giQ tam nhua (hoac bia) thi luc nudc phia dudi mieng coc ep vao td bia se Idn ban phia tren nen nudc phia dudi mieng coc se thoat ngoai, lam tam nhua (hoac bia) rai - C6 the lam thi nghiem Ign ngugc coc nhu tren neu chat long coc la rugu dau (Xem tiep trang 28) Nlmbaingiiy2S.7'20n TAP CHl THI^T B! GIAO Dye - SO 72 • 8/2011 • Zu II HirdNG DAN QUAN U, suf DUNG Chgn vat; nhap World/ Air Resistnee/ non (mac dinh la non)/ Ok Ve 16 xo bang cong cu Spring (Kich chgn Spring, dat tro chugt vao tam vat, dua tro chugt den gap gia dd (theo phuang ngang), roi nhap trai chuot llf^^Z : ",.^^vv^ Hmh Dua vat khoi vi tri can bang mgt khoang nho Nhap Run xem boat canh (hinh 5) Muon bien thj cac vec ta va mo ph6ng bang thj thuc hien cac thao tae nhu da gidi thieu d tren Sau thiet ke xong nhap Save As thuc dan file de luu lai De sil' dung mo hinh thiet ki c6 hai each: Cach 1; Md Working model roi md eac file da thiet ke de trinh chieu; Cach 2: Sir dung phan mem Snaglt quay video boat canh de tao mgt file video roi Import n6 vao bai giang Powerpoit hay Hyperlink file video vao mgt vi tri xac dinh tren Slide ciia bai giang Powerpoit Phan mem Snaglt download tu http://wwH' Snaglt.com Su dung phan mem Working Model chiing ta c6 the thiet ke dugc hau bet cac thi nghiem ao cbo phan ca bgc chuang trinh vat li t '^'.>. * ' Hmh thong No cho hgc sinh cai nhin true quan ve su thay doi van tdc, gia toe va luc tac dung len vat thong qua viec cho phep hien thi cac vec to d6 va viec md ph6ng bang cac thi tuang ung Tai lieu tham khao: http;//www.designsimulation.com/wm2d/index pbp Google/ (PDF) Working model 2D iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiiiiniiiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiniiiiiiiiMiiiiiMnniniiiiMiiiiiiiiiiiiiiiiii^ *» TIEN HANH THI NGHIEM an Nudc uong c6 gas va nudc n6ng khong the lam Ign ngugc coc nhu tren dugc vi n6 lam tang ap suat d tren chat I6ng va lam tam nhua (hoac bia) rai xuong, chat long se chay xuong het Cac em hgc sinh chi nen lam thi nghiem vdi nudc cho dan gian va tiet kiem Thi nghiem khong dugc dimg td bia tham nudc vi mat td bia tiep xue vdi nudc ma nudc tham vao thi td bia bi cong, khong ap sat vao mieng coc dugc 28 • (Tiep theo trang 25) H2 Chiiy: Thi nghiem c6n mgt sd tru'dng hgp khac: Neu tam nhua dat vao mieng cdc cd hinh dang nhu d hinh hoac la mgt tam sat mong (loai TAP CHi THIET Bj GIAO DUC - so 72 • 8/2011 v6 hop sQa dac) thi nudc khong day cdc nhung Ign ngugc cdc thi tim va nudc ben cung khong bj roi xudng mac dii Iiic Ign ngugc coc khong CO gigt nudc nao chay Neu nudc ben day coc (khong cd bgt coc) thi van cd the de cdc Ign xuong d tu the nghieng nhung nudc khong chay khoi coc Nhu'ng trudng hgp phai giai thich bang kien thii'c d trung bgc thong Khi nao hgc den trung hgc thong cac em se van dung de giai thich nhQng hien tugng