🗣️ Trương Thị Sang hỏi: Cho mình hỏi một câu Force Concept Inventory (FCI) - English bài tập về nhà
An elevator is being lifted up an elevator shaft at a constant speed by a steel cable as shown in the following figure. All frictional effects are negligible. In this situation, forces on the elevator are such that
(A) the upward force by the cable is greater than the downward force of gravity.
(B) the upward force by the cable is equal to the downward force of gravity.
(C) the upward force by the cable is smaller than the downward force of gravity.
(D) the upward force by the cable is greater than the sum of the downward force of gravity and a downward force due to the air.
(E) none of the above. (The elevator goes up because the cable is being shortened, not because of an upward force is exerted on the elevator by the cable.)
👩 Đánh giá của giáo viên: Câu này trung bình, mức độ hiểu.
🔑 Chủ đề: trac nghiem.
🕵 Bạn Lê Ngọc Nghĩa trả lời:
Chọn câu (B): the upward force by the cable is equal to the downward force of gravity.
👤 Trần Thị Quốc viết:
Chọn C, the upward force by the cable is smaller than the downward force of gravity.
👤 Lê Thị Thông viết:
Chọn D, the upward force by the cable is greater than the sum of the downward force of gravity and a downward force due to the air.
👤 Phạm Thị Khiêm viết:
Chọn E, none of the above. (The elevator goes up because the cable is being shortened, not because of an upward force is exerted on the elevator by the cable.)
👤 Phạm Thị Phương viết:
Chọn B, the upward force by the cable is equal to the downward force of gravity.
➥ 🗣️ Trương Thị Sang trả lời: Cảm ơn bạn, câu này hình như có trong file doc này Đề của VLTT-03 (Khó và Hay)
👤 Lê Thị Luân viết:
Chọn A, the upward force by the cable is greater than the downward force of gravity.
👤 Lê Thị Đức viết:
Chọn B: the upward force by the cable is equal to the downward force of gravity.
Gửi bạn các file hữu ích đi kèm câu hỏi: