Answer:
From question (a) and (b) the pendulum motion is perpendicular to the force so the normal force will do no work and the tension in the string of the pendulum will not work
And 
so
c
An example will be a where a stone is attached to the end of a string and is made to move in a circular motion while keeping the other end of the string in a fixed position
d
A dog walking along a surface which has friction, here the frictional force would acting in the direction of the motion and this would do positive work
Explanation:
Answer:
160.75 N
Explanation:
The downward velocity has no effect on the force situation, it is only changes in velocity (plus, of course, gravity, which is always there) that require a force. At constant velocity, the bottom spring s_3 is supporting its mass m_3 to balance gravity.
As the elevator slows, though, it also ends up slowing down the spring arrangement, too. However, because the stretching takes time, it means that some damped harmonic motion will be set up in the spring chain.
When the motion has finally damped out, the net force the bottom spring s3 exerts on m3 has two components--that of gravity and of the deceleration of the elevator:
F_3net = m3 * (g + a) = 10.5×(9.81+5.5)= 10.5×15.31= 160.75 N
Magnetic fields
Explanation:
The presence of magnetic fields best explains why a magnet can act a distance on other magnets or on objects containing certain metals.
- Magnetic fields are lines of forces around a bar magnet.
- These lines of forces attracts and repels other magnetic bodies and metallic bodies round it.
- Magnetic lines of forces originates at the north pole and enters in the south pole.
- Areas around a magnetic body are bounded by force fields.
- A magnet has permanent magnetic fields round it.
learn more:
Electromagnet brainly.com/question/2191993
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The density would increase because you still have the same amount of weight, but it is just packed more tightly in a smaller object.
