Hey there,
Friction is important to increase the friction between the bars and the gymnast to prevent the gymnast from falling and hurting themselves.
Hope this helps :))
<em>~Top♥</em>
I would think force. Because friction has to have force to work ^-^
Answer:
the signs of heat and work are; -Q and -W
Explanation:
The first law of thermodynamics is given by; ΔU = Q − W
where;
ΔU is the change in internal energy of a system,
Q is the net heat transfer (the sum of all heat transfer into and out of the system)
W is the net work done (the sum of all work done on or by the system).
Now, The system in this case is the tire and since the air gets warmer, heat must have left the system. Therefore Q is negative (-Q).
Since work is done by the system, W remains negative.
Thus, the signs of heat and work are; -Q and - W
Explanation:
It is given that,
Kinetic energy of the electron, 
Let the east direction is +x direction, north direction is +y direction and vertical direction is +z direction.
The magnetic field in north direction, 
The magnetic field in west direction, 
The magnetic field in vertical direction, 
Magnetic field, 
Firstly calculating the velocity of the electron using the kinetic energy formulas as :



(as it is moving from west to east)
The force acting on the charged particle in the magnetic field is given by :


Since, 
And, 
![F=1.6\times 10^{-19}\times [1178 k-2864.20j]](https://tex.z-dn.net/?f=F%3D1.6%5Ctimes%2010%5E%7B-19%7D%5Ctimes%20%5B1178%20k-2864.20j%5D)


(b) Let a is the acceleration of the electron. It can be calculated as :



Hence, this is the required solution.
Most of the mass is located in the nucleus as suggested by Rutherford's gold foil experiment.