某驾驶员为了粗略测定汽车上货物的质量，采用了这样的办法：让一辆汽车以不变的输出功率P沿一段平直公路匀速行驶，从速度表上读出此时汽车的速度为v。如果汽车运动时受到的阻力与整车重力成正比，比例系数为k，已知汽车自身的质量为M，车上货物的质量设为m。求：
（1） 求货物的质量m；
（2） 如果减少货物质量，使整辆车的质量变为原来整辆车质量的9/10，而汽车的输出功率仍为P，汽车原来沿一段平直公路匀速行驶需要10min。那么，减少质量后，汽车匀速经过同一路段需要多少时间?

A

    Hi, I am Joe. I'm 13 years old. I'm a student in middle school. I'm from Sao Paulo, Brazil, but now I live in Los Angeles, USA.

    I have two brothers and a sister. My brothers are Carlos and Mattias and my sister is Giovanna. My parents are Luisa and J0han. We live in a big house (房子) and we have a dog. My favorite room in the house is my bedroom. There is a big bookcase, a blue bed and a small sofa in my room. Carlos and Mattias are in a room. They have yellow beds, but they don't have a bookcase. My sister's room is nice and tidy. But in my room there are books everywhere.

    In my free time, I like reading and playing sports. My favorite books are about music and sports. I always play soccer or basketball with my friends after school. On Saturdays, I have a music class. On Sundays, I like to pl0y basketball with my father and my brothers.

    I like traveling (旅行)very much I go on trips with my family every holiday (假期)we go to many cities, like London, Tokyo, New York and Paris. We will go to Beijing next time.

根据材料内容判断正误。