题目

谁告诉这些题怎么写那- -(英文好的科学高手进)
1) why does an experiment only ever have ONE independent varible?
2) what is the relationship between mass and inertia of an object?
3) why factors determine the amount of gravitational force?
4) friction depends on what 2 factors?
energy、joules、mechanical energy 、potential energy、kinetic energy、law of conservation of energy、elastic potential energy、gravitational potential energy、chemical potential energy、thermal enerty、nuclear energy、electromagnetic energy、
energy transformation
选项..
1a) a ball held in the air has_____because it is above the floor and____is pulling the ball down.
1b)before the ground moves during an earthquake,the geologic plates that make up the crust are moving under the surface.they build up tremendous strain(_____)before that suddenly break loose and cause an____.
1c) batteries are a source of potential energy.they have___.so does food.
2a)the___of the ball is converted to___when the ball is drop

提问时间：2021-03-22

答案

1.控制变量法.2.inertia is proportional to mass3.mass of earth； distance between the center of earth and the object4.normal force； friction coefficient选择题1.gravitational potential energy；gravity2...