1. Cyclists could ride behind other cyclists to reduce the overall effects of wind resistance
2. Friction = μN --> where N is the normal force and μ is the coefficient of static or dynamic friction. By reducing the weight of the bike the could reduce the reaction force, which is the normal force that acts on them, which is friction is dependent on.
3. Also by getting a smother tire, which reduces the friction between the ground and the tire. This is why professional cyclists have smooth and thin tires meant for speed while mountain bikes generally have large projects called the tread of the tire, to increase friction so they dont slip while biking on rough terrain.
Answer:
Explanation:
Given
Wooden board is pivoted at center and
Older child of mass
is sitting at a distance of L from center
if two child of mass
is sitting at a distance
and
(say) from pivot then net torque about pivot is zero
i.e.

as 
Therefore



Therefore another child is sitting at a distance of 
A) the tension in the string.
Answer: 0.5 m
Explanation:
Given
Mass of the person is 
Trampoline launches the person into the air up to height of 
Force experience by springs is 
Here, the work done on displacing the springs is equivalent to the Potential energy acquired by the person i.e.
![\Rightarrow F\cdot x=mgh\quad [\text{x=displacement of the trampoline}]\\\\\text{Insert the values}\\\\\Rightarrow x=\dfrac{50\times 9.8\times 2}{1960}\\\\\Rightarrow x=\dfrac{980}{1960}\\\\\Rightarrow x=0.5\ m](https://tex.z-dn.net/?f=%5CRightarrow%20F%5Ccdot%20x%3Dmgh%5Cquad%20%5B%5Ctext%7Bx%3Ddisplacement%20of%20the%20trampoline%7D%5D%5C%5C%5C%5C%5Ctext%7BInsert%20the%20values%7D%5C%5C%5C%5C%5CRightarrow%20x%3D%5Cdfrac%7B50%5Ctimes%209.8%5Ctimes%202%7D%7B1960%7D%5C%5C%5C%5C%5CRightarrow%20x%3D%5Cdfrac%7B980%7D%7B1960%7D%5C%5C%5C%5C%5CRightarrow%20x%3D0.5%5C%20m)
Electric potential energy is defined as Ep=Q*V where Q is the magnitude of the charge and V is the potential difference. So when a charge moves between the points that have a potential difference, it's energy changes.
In our case:
Q=2e=2*(-1.6*10^-19) C
V=75 V
Ep=(-3.2*10^-19)*75
Ep=-2.4*10^-17 J
The change in potential energy of the charge is -2.4*10^-17 J