A lightning strike happens so fast, and only hits a point of your body, but if you've noticed that it still completely melts the part of your body that it has stuck? Also the sun is a large mass of that heat, that will melts you the same way as lightning would if it were to continuously strike you all over your body. <span />
There are many types of machine what type well for every day machines like treadmills is sweating, dehydration, loss of calories or fat.
To solve this problem it is necessary to apply the concepts related to energy conservation. Therefore, the work done will initially be equivalent to the change in kinematic energy. And this kinematic energy will be equivalent to the sum of energy (work) carried out by force and friction. In this way we have to
![E = \frac{1}{2} m (v_f^2-v_i^2)](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20m%20%28v_f%5E2-v_i%5E2%29)
![E = \frac{1}{2} (18.8kg)((2.9m/s)^2-(1.5m/s)^2)](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20%2818.8kg%29%28%282.9m%2Fs%29%5E2-%281.5m%2Fs%29%5E2%29)
![E = 57.904J](https://tex.z-dn.net/?f=E%20%3D%2057.904J)
Now,
![E = \Delta W](https://tex.z-dn.net/?f=E%20%3D%20%5CDelta%20W)
![E = W_{Force}+W_{Friction}](https://tex.z-dn.net/?f=E%20%3D%20W_%7BForce%7D%2BW_%7BFriction%7D)
For each one we have
![W_{Force} = F dcos(\theta)](https://tex.z-dn.net/?f=W_%7BForce%7D%20%3D%20F%20dcos%28%5Ctheta%29)
![W_{Force} = (160)(6.20*cos(26))](https://tex.z-dn.net/?f=W_%7BForce%7D%20%3D%20%28160%29%286.20%2Acos%2826%29%29)
![W_{Force} = 891.604J](https://tex.z-dn.net/?f=W_%7BForce%7D%20%3D%20891.604J)
Then at the equation of equilibrium of energy we have,
![57.904J = 891.604J+W_{Friction}](https://tex.z-dn.net/?f=57.904J%20%3D%20891.604J%2BW_%7BFriction%7D)
![W_{Friction} = 57.904-891.604](https://tex.z-dn.net/?f=W_%7BFriction%7D%20%3D%2057.904-891.604)
![W_{Friction} = -833.7J](https://tex.z-dn.net/?f=W_%7BFriction%7D%20%3D%20-833.7J)
Therefore the work done by friction on the chair is -833.7J
Answer: I think it's false
because light travels slower in dense area's.
Answer:
Acceleration is any change in velocity.
Explanation:
Speed is not always changing when accelerating. In fact, when an object moves in a circular path at a constant speed, it is still accelerating, because the direction of its velocity is changing. So the correct answer is velocity.