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| = Which force? = Friction, air resistance, tension, spring force, normal force, etc. are all due to A. Gravitational force A. Electromagnetic force A. Strong force A. Weak force Ans. A |
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Ans. What do you mean by contact? Does exchanging photons/gravitons count as contact? On a more practical level, it is ''very'' helpful to remember, "no contact, no force except gravity, in ''most'' problems of classical mechanics." = The work energy "theorem" = The work energy theorem, $\Delta T = W$ where $T$ is the kinetic energy (and $\Delta T = T_2 - T_1$ is its change) and $W$ is the net work done on the particle, is A. always valid (in classical mechanics). A. valid only for conservative forces. |
Which force?
Friction, air resistance, tension, spring force, normal force, etc. are all due to
- Gravitational force
- Electromagnetic force
- Strong force
- Weak force
Ans. A
The force is everywhere
When two objects exchange forces, they can do so without having to contact each other.
- Yes
- No
Ans. What do you mean by contact? Does exchanging photons/gravitons count as contact? On a more practical level, it is very helpful to remember, "no contact, no force except gravity, in most problems of classical mechanics."
The work energy “theorem”
The work energy theorem, $\Delta T = W$ where $T$ is the kinetic energy (and $\Delta T = T_2 - T_1$ is its change) and $W$ is the net work done on the particle, is
- always valid (in classical mechanics).
- valid only for conservative forces.