first we make a U turn and travel towards home in t = 20 s
so the distance of home from initial position is
![d_1 = v*t_1](https://tex.z-dn.net/?f=d_1%20%3D%20v%2At_1)
![d_1 = 10*20 = 200 m](https://tex.z-dn.net/?f=d_1%20%3D%2010%2A20%20%3D%20200%20m)
Now after picking up the book we travel back with speed 20 m/s
so again after t = 20 s the displacement is given as
![d_2 = v*t = 20*20 = 400 m](https://tex.z-dn.net/?f=d_2%20%3D%20v%2At%20%3D%2020%2A20%20%3D%20400%20m)
so the net displacement is given as
![\vec d = \vec d_2 - \vec d_1](https://tex.z-dn.net/?f=%5Cvec%20d%20%3D%20%5Cvec%20d_2%20-%20%5Cvec%20d_1)
![\vec d = 400 - 200 = 200 m](https://tex.z-dn.net/?f=%5Cvec%20d%20%3D%20400%20-%20200%20%3D%20200%20m)
so it will be displaced by total displacement 200 m
The second one if it’s on edge
The ball's vertical velocity at the time it just passes over the goal is 0 m/s. Its initial vertical velocity is unknown and we denote it by
, where
here is the ball's initial speed. Vertically, the only force acting on the ball is gravity, which attributes a downward acceleration of 9.8 m/s^2. We expect the maximum height achieved by the ball to be 2.4 m, so we can find the initial speed by solving
![\left(0\,\dfrac{\mathrm m}{\mathrm s}\right)^2-\left(v\sin39^\circ\right)^2=2\left(-9.8\,\dfrac{\mathrm m}{\mathrm s^2}\right)(2.4\,\mathrm m)](https://tex.z-dn.net/?f=%5Cleft%280%5C%2C%5Cdfrac%7B%5Cmathrm%20m%7D%7B%5Cmathrm%20s%7D%5Cright%29%5E2-%5Cleft%28v%5Csin39%5E%5Ccirc%5Cright%29%5E2%3D2%5Cleft%28-9.8%5C%2C%5Cdfrac%7B%5Cmathrm%20m%7D%7B%5Cmathrm%20s%5E2%7D%5Cright%29%282.4%5C%2C%5Cmathrm%20m%29)
![\implies v=11\,\dfrac{\mathrm m}{\mathrm s}](https://tex.z-dn.net/?f=%5Cimplies%20v%3D11%5C%2C%5Cdfrac%7B%5Cmathrm%20m%7D%7B%5Cmathrm%20s%7D)
Answer:
288N
Explanation:
Given parameters:
Mass of Cheetah = 12kg
Acceleration = 24m/s²
Unknown:
Force needed by the cheetah to run = ?
Solution:
The force needed by the Cheetah to run is the net force.
According to Newton's law;
Force = mass x acceleration
Insert the given parameters and solve;
Force = 12 x 24 = 288N
Answer:
This does not violate the conservation of energy.
Explanation:
This does not violate the conservation of energy because the hot body gives energy in the form of heat to the colder body, this second absorbs energy. This will be the case until both bodies reach the same temperature, reaching thermal equilibrium and reducing the transfer of thermal energy. In this way the energy was only transferred from one body to another but the total energy of the system (body 1 plus body 2) will be the same as in the beginning, respecting the principle of conservation of energy or also called the first principle of thermodynamics .
The part of physics that studies these processes is in turn called heat transfer or heat transfer or thermal transfer. Heat transfer occurs whenever there is a thermal gradient or when two systems with different temperatures come into contact. The process persists until thermal equilibrium is reached, that is, until temperatures are equalized. When there is a temperature difference between two objects or regions close enough, the heat transfer cannot be stopped, it can only be slowed down.