KT VL 8 một tiết HK II

Họ và tên:.................................................. KIỂM TRA 45 PHUT
Lớp 8/ Môn Vật lí lớp 8

Điểm





Lời nhận xét của Thầy giáo







I. Chọn cụm từ thích hợp điền vào chỗ trống: (Mỗi câu đúng 0,5đ)
1. Các chất được cấu tạo từ .......………………………………………........ gọi là nguyên tử, phân tử
2. Nhiệt độ của vật càng ……………… thì các phân tử chuyển động càng …………….............
3. Nhiệt năng của một vật là ………………………………… của các phân tử cấu tạo nên vật.
4. Có ba hình thức truyền nhiệt là..................................................................................................................................... .........................................................................................................................................................................................................……………………………………………………………..........................................................................
II.
1. Tại sao khi mở lọ nước hoa trong lớp học thì cả lớp đều ngửi thấy mùi nước hoa? (1đ)
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2. (2đ) Tại sao về mùa đông mặc nhiều áo mỏng lại ấm hơn mặc một áo dày? ....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................




III. Bài tập: (3đ)
Anh An mỗi lần kéo được 15 viên gạch lên cao 10m trong thời gian 30 giây, anh Bình mỗi lần kéo được 20 viên gạch lên cao 7m trong thời gian 50 giây. Biết mỗi viên gạch có trọng lượng là 15N.
Tính công của mỗi người sau một lần kéo?
Tính công suất của mỗi người và cho biết ai làm việc khỏe hơn?
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