根据“A force is a push or pull in a specific direction.”、“Gravity is a force that pulls objects together. ”和“Friction (摩擦力) pulls against the sled opposite of gravity. ”可知,本文提到了拉力、推力、重力和摩擦力共4种类型的作用力。故选D。 (3)题详解: 推理判断题。根据“Balanced...
(重力) will pull the sled downward. Gravity is a force that pulls objects together. It keeps everything pulled down to Earth. Gravity always works on an object, even when you push or pull it. Friction (摩擦力) pulls against the sled opposite of gravity. It slows down the sled’s ...
Then, what force is working in the bar being pulled? In the bar being pulled, a force to return to the original shape is working (the magnitude is the same as that of the pulling force). Due to this working force, the bar will return to the original shape if you stop pulling it....
and it allows you to exert this standing-up force your legs exert in a horizontal direction - in each of these pictures, you can see the person with one leg straight back, and the other bent in front of it; at the completion of each step, you could ...
It’s an obvious fact that a person’s strength is limited,while the power of people is unlimited,especially when we stumble and fall. But to beat emeny,we must use collective force.It has been proved in that people work together to combat disaster in Sichuan earthquake .In this natural ...
It is a pulling force and not a pushing force, as it is often misunderstood. Tension acts in the opposite direction of gravitational force. 6. Spring Force When a force is applied on a spring to either compress it or stretch it, the spring exerts an equal force, and that force is call...
a税务 正在翻译,请等待...[translate] apaper cutting 纸切口[translate] aA merchant bank or acquiring bank is a bank that does business with merchants who want to accept payment cards. 一家商业银行或获取银行是做生意与客商想要接受付款卡片的银行。[translate] ...
Theamountof force acting on two charges depends on how far they are from each other. The closer two charges get, the greater the force (either pushing together, or pulling away) becomes. Thanks to electrostatic force, electrons will push away other electrons and be attracted to protons. Thi...
Examples of materials in tension: rope bridges, suspension bridges, telephone wires, tents, steel cables supporting an elevator, and your hair when someone pulls on it.Compression: the pushing force: Compression is a pushing force. It squashes materials. Put your hands together and push hard....
People spend 4 Sundays or sick days in bed all the time and are no worse for wear, but if you don’t start moving again after 24 hours, one of the first things to change is your lungs.Gravity isn’t pulling them down into their normal position anymore, so the lower part of your ...