Biến dạng của vật rắn

Home Lớp 10 Vật lý 10 - Sách kết nối tri thức Bài 33. Biến dạng của vật rắnBài tập trung bình

{"common":{"save":0,"post_id":"8859","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8354","mon_id":"1158790","chapter_id":"1159899","post_id":"8859","question":"M\u1ed9t lò xo có chi\u1ec1u dài t\u1ef1 nhiên 40 cm \u0111\u01b0\u1ee3c treo th\u1eb3ng \u0111\u1ee9ng. Khi treo vào \u0111\u1ea7u t\u1ef1 do c\u1ee7a nó m\u1ed9t v\u1eadt có kh\u1ed1i l\u01b0\u1ee3ng 4 kg thì lò xo có chi\u1ec1u dài 50 cm (\u1edf v\u1ecb trí cân b\u1eb1ng). Tính \u0111\u1ed9 c\u1ee9ng c\u1ee7a lò xo. L\u1ea5y g = 9,8 m\/s².<\/p>","options":[" A.<\/strong> 395 N\/m.","B.<\/strong> 235 N\/m.","C.<\/strong> 392 N\/m.","D.<\/strong> 125 N\/m."],"correct":"3","level":"2","hint":"","answer":"Ch\u1ecdn C.<\/strong> 392 N\/m.<\/span><\/p>Khi v\u1eadt cân b\u1eb1ng, ta có: <\/p>$F_{\u0111h}=P\\;$<\/span>⇒ $k.|\\Delta\\ell|=mg$<\/span> ⇒ $k=\\dfrac{mg}{|\\Delta\\ell|}=\\dfrac{4.9,8}{0,5-0,4}=392(N\/m)$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-14 08:38:48","option_type":"txt","len":1},{"id":"8355","mon_id":"1158790","chapter_id":"1159899","post_id":"8859","question":"M\u1ed9t lò xo có \u0111\u1ed9 c\u1ee9ng k = 50 N\/m, \u0111\u1ea7u trên \u0111\u01b0\u1ee3c móc vào \u0111i\u1ec3m treo c\u1ed1 \u0111\u1ecbnh, \u0111\u1ea7u d\u01b0\u1edbi g\u1eafn v\u1eadt nh\u1ecf có kh\u1ed1i l\u01b0\u1ee3ng m. Bi\u1ebft r\u1eb1ng khi cân b\u1eb1ng lò xo dài thêm 10 cm. Tính kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt n\u1eb7ng, l\u1ea5y g = 10 m\/s².<\/p>","options":["A.<\/strong> 0,2 kg.","B.<\/strong> 0,5 kg.","C.<\/strong> 0,4 kg.","D.<\/strong> 0,8 kg."],"correct":"2","level":"2","hint":"","answer":"Ch\u1ecdn B.<\/strong> 0,5 kg.<\/span><\/p>Khi v\u1eadt cân b\u1eb1ng, ta có: <\/p>$F_{\u0111h}=P\\;$<\/span>⇒ $k.|\\Delta\\ell|=mg$<\/span> ⇒ $m=\\dfrac{k.|\\Delta\\ell|}{g}=\\dfrac{50.0,1}{10}=0,5(kg)$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-14 08:39:53","option_type":"txt","len":0},{"id":"8357","mon_id":"1158790","chapter_id":"1159899","post_id":"8859","question":"M\u1ed9t lò xo có chi\u1ec1u dài t\u1ef1 nhiên $\\ell_o=30\\;cm$<\/span>, \u0111\u1ed9 c\u1ee9ng k = 10 N\/m \u0111\u1ea7u trên \u0111\u01b0\u1ee3c treo vào \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh. \u0110\u1ea7u d\u01b0\u1edbi c\u1ee7a lò xo \u0111\u01b0\u1ee3c g\u1eafn v\u1edbi v\u1eadt n\u1eb7ng có kh\u1ed1i l\u01b0\u1ee3ng m = 150 g. Tìm chi\u1ec1u dài lò xo khi nó \u1edf tr\u1ea1ng thái cân b\u1eb1ng, l\u1ea5y g = 10 m\/s².<\/p>","options":["A.<\/strong> 15 cm.","B.<\/strong> 30 cm.","C.<\/strong> 45 cm.","D.<\/strong> 60 cm."],"correct":"3","level":"2","hint":"","answer":"Ch\u1ecdn C.<\/strong> 45 cm.<\/span><\/p>- Khi v\u1eadt cân b\u1eb1ng, ta có: <\/p>$F_{\u0111h}=P\\;$<\/span>⇒ $k.|\\Delta\\ell|=mg$<\/span> ⇒ $|\\Delta\\ell|=\\dfrac{mg}{k}=\\dfrac{0,15.10}{10}=0,15(m)$<\/span> = 15 (cm).<\/p>- Chi\u1ec1u dài lò xo khi v\u1eadt \u1edf tr\u1ea1ng thái cân b\u1eb1ng:<\/p>$\\ell_{cb}=\\ell_o+\\Delta\\ell=30 + 15=45(cm)$<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-14 08:44:07","option_type":"txt","len":0}]}