Explanation:
It is given that,
Force on grindstone, F = 180 N
Radius of grindstone, r = 0.28 m
Mass of grindstone, m = 75 kg
We need to find the angular acceleration of the grindstone. In rotational motion, the relation between the torque and angular acceleration is given by :


I is the moment of inertia of solid disk, 
is the torque exerted, 




So, the angular acceleration of the disk is
. Hence, this is the required solution.
Gravity or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another. - google
Answer:
B) 71.5 [km]
Explanation:
To solve this problem we will decompose each of the directions in the x & y axes.
To solve this problem we will decompose each of the directions in the x & y axes. also for a greater understanding of the angles, you should look at the attached image, which contains the orientations for each angle (clockwise or counterclockwise).
<u>59.0 km in a direction 30.0° east of north</u>
<u />
![d_{1x}= 59*sin(30) = 29.5[km]\\d_{1y}= 59*cos(30) = 51.09[km]](https://tex.z-dn.net/?f=d_%7B1x%7D%3D%2059%2Asin%2830%29%20%3D%2029.5%5Bkm%5D%5C%5Cd_%7B1y%7D%3D%2059%2Acos%2830%29%20%3D%2051.09%5Bkm%5D)
<u>58.0 km due south</u>
<u />
![d_{2y} = - 58 [km]\\](https://tex.z-dn.net/?f=d_%7B2y%7D%20%3D%20-%2058%20%5Bkm%5D%5C%5C)
<u>It flies 100 km 30.0° north of west</u>
<u />
<u />
<u />
<u />
Now we sum algebraically the components
![d_{x}=29.5-86.6 = -57.1[km]\\d_{y}=51.09 -58+50=43.09[km]\\\\](https://tex.z-dn.net/?f=d_%7Bx%7D%3D29.5-86.6%20%3D%20-57.1%5Bkm%5D%5C%5Cd_%7By%7D%3D51.09%20-58%2B50%3D43.09%5Bkm%5D%5C%5C%5C%5C)
Using the Pythagorean theorem we can find the magnitude of the displacement.
![d = \sqrt{(57.1)^{2} +(43.09)^{2} } \\d= 71.53[km]](https://tex.z-dn.net/?f=d%20%3D%20%5Csqrt%7B%2857.1%29%5E%7B2%7D%20%2B%2843.09%29%5E%7B2%7D%20%7D%20%5C%5Cd%3D%2071.53%5Bkm%5D)
Answer:
When you jump down, your kinetic is converted to potential energy of the stretched trampoline. The trampoline's potential energy is converted into kinetic energy, which is transferred to you, making you bounce up. At the top of your jump, all your kinetic energy has been converted into potential energy. Right before you hit the trampoline, all of your potential energy has been converted back into kinetic energy. As you jump up and down your kinetic energy increases and decrease.
In will most likely decrease its speed.
hope this helps.