A child is sitting in a chair that hangs from a massless rop
来源:学生作业帮 编辑:拍题作业网作业帮 分类:英语作业 时间:2024/05/19 06:49:03
A child is sitting in a chair that hangs from a massless rope.The rope hangs over a frictionless tree branch and runs back into the child's hands.The combined mass of the child and the chair is 32.1 kg.The child's older sister offers to help pull the chair up the tree.What force must she exert on the rope - from the ground - in order to pull the chair upward with a constant speed?
Answer:
Answer:
一个儿童坐在一个椅子上,这个椅子上系一根轻质绳,这根绳子绕过树叉,另一端在儿童手里.儿童和椅子总质量为32.1Kg.这个儿童的姐姐至少需要提供一个多大的支持力才能使儿童和椅子不断上升
321N
321N
The child ____on the chair and eating a cake .A sitting B is
She'sitting _____ in a chair and her sister is sitting ___ a
There is a child sitting on the chair(复数句)
坐在椅子上是 sitting on a chair / sitting in a chair / sitting dow
the boy is sitting on a chair
Susan is sitting ____ a chair in the garden. A.in B.on
he was sitting in the chair,( )a book.A read
the old man is sitting in a chair,-----pipe in ----mouth.
That is a chair.改可定句
小学英语二年级选择题Grandma is sitting _______the chair? A in B on C u
John painted her sitting in a chair with het hands().
I’m just an old man,sitting in a chair.