Hi there!
To find the appropriate force needed to keep the block moving at a constant speed, we must use the dynamic friction force since the block would be in motion.
Recall:
![\large\boxed{F_D = \mu N}}](https://tex.z-dn.net/?f=%5Clarge%5Cboxed%7BF_D%20%3D%20%5Cmu%20N%7D%7D)
The normal force of an object on an inclined plane is equivalent to the vertical component of its weight vector. However, the horizontal force applied contains a vertical component that contributes to this normal force.
![\large\boxed{N = Mgcos\theta + Fsin\theta}}](https://tex.z-dn.net/?f=%5Clarge%5Cboxed%7BN%20%3D%20Mgcos%5Ctheta%20%2B%20Fsin%5Ctheta%7D%7D)
We can plug in the known values to solve for one part of the normal force:
N = (1)(9.8)(cos30) + F(.5) = 8.49 + .5F
Now, we can plug this into the equation for the dynamic friction force:
Fd= (0.2)(8.49 + .5F) = 1.697 N + .1F
For a block to move with constant speed, the summation of forces must be equivalent to 0 N.
If a HORIZONTAL force is applied to the block, its horizontal component must be EQUIVALENT to the friction force. (∑F = 0 N). Thus:
Fcosθ = 1.697 + .1F
Solve for F:
Fcos(30) - .1F = 1.697
F(cos(30) - .1) = 1.697
F = 2.216 N
Answer:
Mechanical vs. Quartz Watch Movements
Mechanical watch movements are powered by gears and springs. They're autonomous little machines without the need for electric power sources, whereas quartz watches are powered by batteries that vibrate little crystals.
Answer:
convection
Explanation:
Heat transfer by convection is caused by differences of temperature and density within a fluid.