如图所示，小圆环A吊着一质量为m2的物块并套在另一个竖起的大圆环上，有一细线拴在小圆环A上，另一端跨过固定在大圆环最高点B的一个小滑轮后吊着一个质量为m1的物体，如果不计一切摩擦，平衡时弦AB所对的圆

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如图所示，小圆环A吊着一质量为m₂的物块并套在另一个竖起的大圆环上，有一细线拴在小圆环A上，另一端跨过固定在大圆环最高点B的一个小滑轮后吊着一个质量为m₁的物体，如果不计一切摩擦，平衡时弦AB所对的圆心角为θ，则两物块的质量之比m₁：m₂为（　　）

A： $2 s i n \frac{θ}{2}$

B： $2 c o s \frac{θ}{2}$

C：cos $\frac{θ}{2}$

D：sin $\frac{θ}{2}$

上一题下一题 0.0难度选择题更新时间:2019-03-04 11:24:57

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A

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Business is the organized approach to providing customers with the goods and services they want. The word business also refers to an organization that provides these goods and services. Most businesses seek to make a profit—that is, they aim to achieve income that is more than the costs of operating the business.____. Commonly called nonprofits，these organizations are primarily nongovernmental service providers. ____

Business management is a term used to describe the techniques of planning, direction，and control of the operations of a business. ____. One is the establishment of broad basic policies with respect to production; sales; the purchase of equipment, materials and supplies; and accounting. ____. The third relates to the establishment of standards of work in all departments. Direction is concerned primarily with supervision(监管) and guidance by the management in authority.____.

A. Examples of nonprofit businesses include such organizations as social service agencies and many hospitals.

B. Control includes the use of records and reports to compare actual work with the set standards for work.

C. In this connection there is the difference between top management and operative management.

D. However, some businesses only seek to earn enough to cover their operating costs.

E. The second aspect relates to the application of these policies by departments.

F. In the theory of business management, organization has two main aspects.

G. Planning in business management has three main aspects.

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