What is a friction force? What is the friction force? What is the SI unit of force? 1. We know that there is a force between every two objects in the universe, but is there any answer to why there is a force? 2. What causes this force? What is frictional force? What is the un...
A. Magnetic force B. Gravitational force C. Electrical force D. Frictional force 相关知识点: 试题来源: 解析 B。解析:球落到地面是因为重力的作用。选项 A 磁力通常作用于磁性物体之间;选项 C 电力作用于带有电荷的物体之间;选项 D 摩擦力是阻碍物体相对运动的力,与球下落无关。反馈...
What is a significant factor that can affect free fall? A. Magnetic force B. Electric force C. Air resistance D. Nuclear force 相关知识点: 试题来源: 解析 C。解析:文中提到“There are several factors that can affect free fall. Air resistance is a significant factor.”。 反馈 收藏 ...
A. Magnetic force B. Electric force C. Gravitational force D. Frictional force 相关知识点: 试题来源: 解析 C。解析:使物体向地球下落的力是重力。文章中有关于力的介绍。选项 A 磁力不是使物体向地球下落的力。选项 B 电力与物体下落无关。选项 D 摩擦力是阻碍物体相对运动的力。反馈...
A. Magnetic force B. Gravitational force C. Electrical force D. Frictional force 相关知识点: 试题来源: 解析 B。A 选项磁力有特定的磁性物体才会产生吸引力;C 选项电力是与电荷相关的力;D 选项摩擦力是阻碍物体相对运动的力。而重力是地球对物体的吸引力,使物体有向地球靠近的趋势。反馈...
What causes a magnetic field? What is Earth's magnetic field made of? How strong is the magnetic field in an MRI? What kind of magnetic field is produced by a solenoid? Is gravity a magnetic field? What is the difference between magnetic flux and magnetic field?
Physics - Classical PhysicsWe show that attempts to modify the force on a magnetic dipole by introducing either hidden momentum or internal forces are not correct. The standard textbook result ${\\\bf F=abla(\\\bmu\\\cdot B)}$ is correct even in the presence of time dependent electromagne...
The atoms that make up the molecules of all matter have a nucleus of neutrons and protons. Orbiting around all of the nuclei areelectronsthat carry a negative charge. The shape of their orbits gives the atoms a directional orientation, and the orbital motion causes a very weak magnetic field...
What causes magnetic permeability? Magnetic permeability is influenced by the magnetic flux intensity and strength of the magnetizing field. Factors such as the nature of the material, temperature, and frequency of force applied may also affect the magnetic permeability of the material. How do you ...
We show that attempts to modify the force on a magnetic dipole by introducing either hidden momentum or internal forces are not correct. The standard textbook result ${\\bf F=abla(\\bmu\\cdot B)}$ is correct even in the presence of time dependent electromagnetic fields. Using this expressi...