400分____6时

    Hello! I'm Sally. I'm an English girl. Now I'm in Beijing with1parents. Today is Sunday. I2to Yangguang Clothes Store. Wow! I see lots of3clothes in it. They have sweaters at a good4. They have some bags5sports. They have hats in red, black6yellow. The white7are on sale. They8only 15 dollars. I think they are cheap(便宜的), so I9a small one for myself and a large one for my10.

请回答下列问题：

如图所示矿泉水瓶的总质量为500g，用手握住竖直的矿泉水瓶不动，瓶受到的摩擦力方向____，大小为____N（g取10N/kg），如果增大握力则瓶子受到的摩擦力____（选填“变小”、“变大”或“不变”）