题目

在海滨游乐园里有一种滑沙的游乐活动。如图所示，人坐在滑板上从斜坡的高处A点由静止开始滑下，滑到斜坡底部B点后沿水平滑道再滑行一段距离到C点停下来。斜坡滑道与水平滑道间是平滑连接的，滑板与两滑道间的动摩擦因数均为μ=0.50，不计空气阻力，重力加速度g=10m/s2。(1) 若斜坡倾角θ=37°，人和滑板的总质量m=60 kg。求人在斜坡上下滑时的加速度大小；（sin37°=0.6，cos37°=0.8）(2)由于受到场地限制，A点到C点的水平距离只有s=50m,为确保人身安全,阅读理解(阅读短文，判断对错。对的填“T”，错的填“F”)。I want to buy a present for my mum. I’ve got twenty yuan. The necklace is beautiful. Wow! It’s expensive. It costs six hundred yuan. The brooch(胸针) is beautiful. It costs eighty yuan. The flowers are beautiful. One flower costs three yuan. I can buy a bunch of flowers for mum.【1】The necklace is cheap, but it isn’t beautiful.（_____）【2】The brooch is very beautiful. （_____）【3】The flowers are beautiful and cheap. （_____）