问题 问答题

小明同学学习物理后养成了观察、思考生活的好习惯.他的质量是50千克,一次骑自行车上学,在水平路面上以4m/s的速度匀速行驶.有关数据如表所示.(g取10N/kg)

(1)小明同学骑车沿直线匀速行驶10min前进的距离是多少?

自行车净重200N
行驶时自行车与地总接触面积0.01m2
匀速行驶过程中的总阻力30N
轮胎承受的最大压强1.2×105Pa
(2)在行驶过程中,小明和车对地面的压强是多大?

答案

已知:速度v=4m/s,时间t=10min=600s,人的质量m=50kg,车重G=200N,g=10N/kg,行驶时自行车与地总接触面积S=0.01m2

求:(1)10min前进的距离s=?;(2)小明和车对地面的压强p=?

(1)∵v=

s
t

∴骑自行车行驶的距离:

s=vt=4m/s×600s=2400m;

(2)人的重力G人=mg=50kg×10N/kg=500N,

自行车对地面的压力:

F=G+G=500N+200N=700N,

自行车对地面的压强:

p=

F
S
=
700N
0.01m2
=7×104Pa.

答:(1)10min前进的距离为2400m;

(2)小明和车对地面的压强为7×104Pa.

阅读理解
阅读下列材料,从所给的六个选项(A、B、C、D、E和F)中,选出符合各小题要求的最佳选项,并把答案写在答题卡对应的位置上。选项中有一项为多余选项。
以下是6条有关颜色偏好和性格关系的描述。
A
GOLD
People who choose GOLD as their primary color like to fit in or belong. They tend to be reliable people who enjoy serving others. Things like tradition and home are very important to them. They need order and structure. They don’t like waste or change.
B
ORANGE
People who choose ORANGE as their primary color need variety and freedom. They take pride in being highly skilled. They enjoy “hands-on” work and often are good in a crisis. They are risk-takers and challenge-seekers.
C
YELLOW
People who choose YELLOW as their primary color are curious about everything. They are confident and knowledgeable. They love sports very much and they work highly efficiently.
D
GREEN
People who choose GREEN as their primary color are competent and want to control the realities of life. They are analytical and enjoy solving problems and developing systems. They love intelligence and logic. They are often critical of themselves and others.
E
BLUE
People who choose BLUE as their primary color enjoy close relationships, harmony and integrity(正直). They are often very creative and they also enjoy the creative work of others.
F
RED
People who choose RED as their primary color are always full of vigor and tend to be confident. It seems that they are ready to do anything and will be successful. They also have a strong desire for power.
现在阅读以下根据员工性格提出的促进工作效率的方法,然后从以上A, B, C, D, E和F中找出与它们适合的群体。
小题1:Create a warm and personal working atmosphere; Establish a peaceful working environment and try to avoid conflict(冲突); Allow them freedom to express their feelings; Praise them for their creativity.
小题2:Assign them work needing detailed planning; Define the tasks in clear terms; Provide a stable work environment and avoid sudden change; Issue rules and regulations; Provide good examples.
小题3:Assign them work which needs analytical thinking and problem-solving skills; Encourage them to think independently and take their ideas to the next step.
小题4:Assign them work which is action-packed; Provide opportunities which need skills and challenges; Do not let them do the same job for a long time.
小题5:Assign them work which needs full energy; Provide competitive opportunities; Let them know that they will be promoted if they do brilliantly.
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