问题 填空题

如图a所示,用铁架台、弹簧和多个已知质量且质量相等的钩码,探究在弹性限度内弹簧弹力与弹簧伸长量的关系.

①为完成实验,还需要的实验器材有:______.

②图b是弹簧所受弹力F与弹簧伸长量x的关系图线,由此可求出弹簧的劲度系数为______N/m.图线不过原点的原因是由于______.

答案

①需要测弹簧的长度、形变量,故还需要的实验器材有:刻度尺

    ②有图象可知,斜率表示弹簧的劲度系数,k=

7
0.035
=200N;

    图线不过原点的原因是由于弹簧有自重,使弹簧变长.

故答案为  刻度尺   200   弹簧有自重

单项选择题

Millions of Americans and foreigners see GI.Joe as a mindless war toy, the symbol of American military adventurism, but that’ s not how it used to be. To the men and women who (1) in World War I1 and the people they liberated, the GI. was the (2) man grown into hero, the pool farm kid torn away from his home, the guy who (3) all the burdens of battle, who slept in cold foxholes, who went without the (4) of 1hod and shelter, who stuck it out and drove back the Nazi reign of murder. This was not a vohmteer soldier, not someone well paid, (5) an average guy, up (6) the best trained, best equipped, fiercest, most brutal enemies seen in centuries.

His name is not much. GI. is just a military abbreviation (7) Govermnent Issue, and it was on all of the article (8) to soldiers. And Joe A common name for a guy who never (9) it to the top. Joe Blow, Joe Magrae... a working class name.The United States has (10) had a president or vieepresident or secretary of state Joe.

GI. Joe had a (11) career fighting Geman, Japanese, and Korean troops. He appears as a character, or a (12) of American personalities, in the 1945 movie The Story of GL Joe, based on the last days of war correspondent Ernie Pyle. Some of the soldiers Pyle (13) portrayde themselves in the fihn. Pyle was famous for covering the (14) side of the warl, writing about the dirt-snow-and-mud soldiers, not how many miles were (15) or what towns were captured or liberated. His reports (16) the "willie" cartoons of famed Stars and Stripes artist Bill Maulden. Both men (17) the dirt and exhaustion of war, the (18) of civilization that the soldiers shared with each other and the civilians: coffee, tobacco, whiskey, shelter, sleep. (19) Egypt, France, and a dozen more countries, G. I. Joe was any American soldier, (20) the most important person in their lives.

(14)()

A.ethical

B.military

C.political

D.human

多项选择题