A motion diagram represents the motion of an object by displaying its location at various equally spaced times on the same diagram. Motion diagrams are a pictorial description of an object's motion. They show an object's position and velocity initially, and present several spots in the center of the diagram.
Answer:
In this movement, both the magnitude and the direction of the force change
Explanation:
A body that moves in an elliptical path must be subjected to a force that is pointed towards one of the foci, therefore the force is central.
The magnitude of this force must be greater when the two bodies are closer and its directional changes, but it always points to the focus where the body that originates the force is.
In this movement, both the magnitude and the direction of the force change
Answer:
μs = 0.36
Explanation:
Assuming no other forces acting on the cup while the car is decelerating, the friction force is responsible for any horizontal movement of the cup.
If the cup is on the verge of starting to slide, the friction force can be expressed as follows:
Ff = -μs*N = -μs*m*g
This force produces a deceleration from 45 Kmh to rest, in 3.5 s or more.
Converting 45 kmh to m/s, we have:
![45 kmh *\frac{1000m}{1km} * \frac{1h}{3600 s} = 12.5 m/s](https://tex.z-dn.net/?f=45%20kmh%20%2A%5Cfrac%7B1000m%7D%7B1km%7D%20%2A%20%5Cfrac%7B1h%7D%7B3600%20s%7D%20%3D%2012.5%20m%2Fs)
We can find the acceleration, just applying the definition, with vf =0, as follows:
![a = \frac{-vf}{t} =\frac{-12.5m/s}{3.5s} = -3.57 m/s2](https://tex.z-dn.net/?f=a%20%3D%20%5Cfrac%7B-vf%7D%7Bt%7D%20%3D%5Cfrac%7B-12.5m%2Fs%7D%7B3.5s%7D%20%3D%20-3.57%20m%2Fs2)
According to Newton's 2nd law, we can write the following expression:
F = m*a = -μs*m*g
Simplifying common terms, we can solve for μs, as follows:
μs = ![\frac{a}{-g} =\frac{-3.57 m/s2}{-9.80m/s2} = 0.36](https://tex.z-dn.net/?f=%5Cfrac%7Ba%7D%7B-g%7D%20%3D%5Cfrac%7B-3.57%20m%2Fs2%7D%7B-9.80m%2Fs2%7D%20%3D%200.36)