Dùng 3 ròng rọc cố định và 3 ròng rọc động để đưa một vật lên cao thì đc lợi bao nhiêu lần về lực và thiệt bao nhiêu lần về đường đi. Vẽ hình. Giúp mik vs trả vote 5 sao nha!

Biết rằng 4'2 =16 . Có còn số nguyên nào khác mà bình phương của nó cũng bằng 16 ?

Cho hình thang vuông ABCD có AB//CD (góc A=90 độ),AB=4cm,CD=9cm,AD=6cm 1.CM: tam giác BAD đồng dạng tam giác ADC 2.CM:AC vuông góc BD 2.Cho tam giác ABC vuông tại A có AH là đường cao(H thuộc BC)kẻ HD vuông AC tại D(DE thuộc AC) 1. CM: tam giác DHA đồng dạng HAC 2. Gọi O là trung điểm AB, OC cắt AH,HD lần lượt tại K và I. Chứng minh: HI=ID 3. Chứng minh: AD.AC=BH.HC

Cho tam giác ABC vuông ở A,đường cao AH.Từ điểm D nằm giữa H và C,vẽ DE vuông góc D(E thuộc AC),DK vuông góc AC(K thuộc AC).C/M BE//HK Giúp mình với mình cần gấp ạ

Hòa tan hoàn toàn 5,6 gam Fe bằng dung dịch axit HCl. Sau phản ứng thấy có khí thoát ra ở đktc và dung dịch X. a/ Tính khối lượng muối thu được. b/ Tính thể tích khí thoát ra (đktc) c/ Tính nồng độ mol của dung dịch HCl, biết thể tích HCl đã dùng là 200ml.

Giúp mik bài 4 vs mn mik đang gấp

Viết 10 câu ghép rồi xác định chủ nhũ vị ngữ

Bài 8 giúp mik nha .Cảm ơn nhiều

VII. Read the text. Then choose the right answer A, B, C or D. Last year, we had a nice holiday. My friend and I went to the seaside for a month. I had been to the seaside several times before, but this was the first time for my friend. Naturally, it was the great event for him. Finally, the day came. It was a fine morning. We got up very early because we wanted to leave home after breakfast. We made the journey by car. We reached the seaside at noon. We spent many hours on the beach. We enjoyed making castles and channels in the sand. People said we ought to spend at least a few weeks here. If we could stay longer, so much the better. 39. How long did the writer and his friend spend at the seaside? A. week B. A few weeks C. A month D. A few months 40. Who went to the seaside the first time? A. The writer B. The writer and his friend. C. The writer's family. D. The writer's friend. 41 . What was the weather like on the day they started their journey to the seaside? A. It was bad. B. It was rainy. C. It was snowy. D. It was nice. 42. How did they travel to the seaside? A. By car B. By train C. By bus D. By air 43. When did they reach the seaside? A. At 8 o'clock B. At 12 o'clock C. At 4 p.m D. At 9 p.m 44. What did they enjoy making in the sand? A. They enjoyed making castles. B. They enjoy to make castles and channels. C. They enjoyed to make castles and channels.D. They enjoyed making castles and channels. 45. The word "here" in the sixth line means "______" A. at the seaside B. castles C. channels D. in the sand 39. 40. 41. 42. 43. 44 45.

Traffic jam (1. to be)_______________ a common sight in big cities like Delhi, Mumbai, Calcutta etc. This is due to (2. increase) _______________ population of the metropolitan cities. People from far off places rush towards big cities to (3. earn) _______________as big cities (4. have)_______________many options and possibilities for them. Then there are permanent citizens also. So with the human traffic, vehicular traffic also increases. As the standard of living is (5. become_______________ high everyone wants to (6.purchase)_______________his own car.