1) Acceleration of the sled
The acceleration of the sled is given by the net force acting in the direction parallel to the incline. There are two forces acting along this direction: the component of the weight parallel to the ramp (downward) and the friction (upward). Therefore, the net force acting in this direction is
And the acceleration is given by Newton's second law:
2) Normal force
The normal force acting on the sled is equal to the component of the weight perpendicular to the incline, therefore:
In unmagnetized materials the domains are randomly aligned in different directions and cancel each other out. In a magnet all the domains are oriented in the same direction. In the case of a nail, the domains can be aligned in the same direction causing the nail to become magnetic.
NO net force is required to keep a moving object moving in a straight
line at a constant speed. In fact, if you apply ANY force to it, in ANY
direction, then its speed, its direction, or both must change, and its
velocity won't be uniform any more.
I know we never see this in our daily life. Whenever we see an object
moving, it always stops. That's because the net force on it is never zero ...
there's always some gravity or some friction acting on it. That's what you
have to put up with when you live on Earth.
Answer:
Doppler effect
Explanation:
this means that at one point when the person running is close to the observer it will appear to run fast but slower as he moves away from the observer
