1.单选题- (共3题)
①荡秋千经过最低点的小孩
②汽车过凸形桥
③汽车过凹形桥
④在绕地球作匀速圆周运动的飞船中的仪器
A.①② |
B.①③ |
C.①④ |
D.③④ |
A.增大速度快速通过桥顶 |
B.以任何速度匀速通过桥顶都可以 |
C.以尽可能小的速度通过桥顶 |
D.使通过桥顶的向心加速度尽可能小 |

A. 若拉力突然消失,小球将沿轨迹Pa做离心运动
B. 若拉力突然变小,小球将沿轨迹Pa做离心运动
C. 若拉力突然变小,小球将可能沿轨迹Pb做离心运动
D. 若拉力突然变大,小球将可能沿轨迹Pc做向心运动
2.选择题- (共3题)
Do you love Beats headphones, True Religion jeans, and UGG shoes? These are some of the most popular brands (牌子) around. They are also expensive. But some experts say they are not much better than cheaper brands.
For example, Jim Wilcox works for Consumer Reports. He tested all kinds of headphones. He says that $80 Koss Pro headphones provide basically the same quality (质量) and comfort as Beats. So why do people pay twice or even 10 times as much for the hottest brands?
Experts say it's because fashionable, expensive brands send a message. Brands say “I belong” or “I can afford it.”
Some people think that expensive brand names are worth the price. They say that some designer clothes really are top quality and that they last longer than cheaper brands. Some teenagers choose to wear popular brands because these brands make them feel good about themselves.
Alexandra Allam, 17, likes to buy brand-name products. “I'd rather spend the extra money to get something I know I'll be satisfied with,” she says. Her friend Emmy Swan agrees, saying “As long as you can afford it, it seems reasonable to buy what you want.” But not all teenagers agree. “Spending hundreds of dollars for designer sunglasses is stupid and unreasonable,” says Daniel Steinbrecher, 16. “It's fake (假的) happiness.”
People who are against wearing expensive brand names say that many designer brands aren't any better. “It's wasteful to buy things just because they are popular,” says Edmund Williams, 15. “You'll feel better if you buy things because you like them. If you have extra money to spend, it would be better to give it to people in need.”
3.多选题- (共1题)
A.当火车以速率v0行驶时,火车的重力与支持力的合力方向一定沿水平方向 |
B.当火车的速率v>v0时,火车对外轨有向外的侧向压力 |
C.当火车的速率v>v0时,火车对内轨有向内的挤压力 |
D.当火车的速率v<v0时,火车对内轨有向内侧的压力 |
4.解答题- (共4题)



(1)在最高点水不流出的最小速率.
(2)水在最高点速率v=3 m/s时,水对杯底的压力大小.
-
【1】题量占比
单选题:(3道)
选择题:(3道)
多选题:(1道)
解答题:(4道)
-
【2】:难度分析
1星难题:0
2星难题:0
3星难题:0
4星难题:0
5星难题:0
6星难题:2
7星难题:0
8星难题:3
9星难题:3