Asoccer player swings his leg forward to kick the ball. if his leg has a moment of inertia of 0.9 kg m2, and is initially at rest, how much torque must he generate with his hip flexor muscle in order to reach an angular velocity of -8 rad/s in 0.5 seconds?

14.4 Nm

Explanation:

Moment of Inertia, I = 0.9 kg m^2, w0 = 0, w = 8 rad/s, t = 0.5 second

Use first equation of motion for rotational motion

w = w0 + α t

where, α be the angular acceleration

8 = 0 + α x 0.5

α = 16 rad/s^2

Now Torque = Moment of inertia x angular acceleration

τ = I x α

τ = 0.9 x 16 = 14.4 Nm

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

blue light is scattered in different directions by the tiny molecules of air. blue is scattered more than other colours because it has a shorter distance to travel which results in smaller waves. this is why we see a blue sky most of the time.