Answer:
We will use Potential Energy Formula
Potential Energy = mass × gravitation × height
PE = 0,55 × 10 × 4
PE = 22 J (A)
Answer:
A
Explanation:
When two magnets are brought near each other, like poles repel; opposite poles attract. We like to represent this force effect of a magnet on iron-like objects with a concept called magnetic field. The concept of field can be best understood if we remember the gravitational force of Earth on object near it.
Answer:
The speed of disk is 1.98 ![\frac{m}{s}](https://tex.z-dn.net/?f=%5Cfrac%7Bm%7D%7Bs%7D)
Explanation:
Given:
Mass of
kg
Spring constant ![k = 244 \frac{N}{m}](https://tex.z-dn.net/?f=k%20%3D%20244%20%5Cfrac%7BN%7D%7Bm%7D)
Compression of spring
m
From energy conservation theorem,
Spring potential energy converted into kinetic energy,
![\frac{1}{2} m v^{2} = \frac{1}{2} k x^{2}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20m%20v%5E%7B2%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20k%20x%5E%7B2%7D)
![v = \sqrt{\frac{k x^{2} }{m} }](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B%5Cfrac%7Bk%20x%5E%7B2%7D%20%7D%7Bm%7D%20%7D)
![v = \sqrt{\frac{244 \times 16 \times 10^{-4} }{0.099} }](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B%5Cfrac%7B244%20%5Ctimes%2016%20%5Ctimes%2010%5E%7B-4%7D%20%7D%7B0.099%7D%20%7D)
![v = 1.98 \frac{m}{s}](https://tex.z-dn.net/?f=v%20%3D%201.98%20%5Cfrac%7Bm%7D%7Bs%7D)
Therefore, the speed of disk is 1.98 ![\frac{m}{s}](https://tex.z-dn.net/?f=%5Cfrac%7Bm%7D%7Bs%7D)
Answer:
negatively charged object attract other negatively objects
Explanation:
opposites attract
Answer:
The acceleration at the astronaut's head decreases.
Explanation:
Since the centripetal acceleration equals acceleration due to gravity,
a = g = GM/R². since a changes infinitesimally from his foot to his head, we differentiate a with respect to r to get da/dr = -2GM/R³.
So, da, the change in acceleration = -2GMdR/R³ = -2gdR/R = -2 × 9.8/6.4 × 10⁶ m = -3.0625 × 10⁻⁶dR m/s².
Since dR = height of astronaut = 1.80 m, da = -3.0625 × 10⁻⁶ × 1.8 = -5.5125 × 10⁻⁶ m/s².
So the acceleration at the astronaut's head is g + da = 9.8 - 0.0000055125 = 9.7999944875 m/s².
So the acceleration at the astronaut's head decreases.