A race car driving on a banked track that makes an angle θ with the horizontal rounds a curve for which the radius of curvature is R.

Part A

There is one speed vcritical at which friction is not needed to keep the car on the track. What is that speed in terms of θ and R? Express your answer in terms of the variables R, θ, and the acceleration due to gravity g. vcritical =

Part B

If the coefficient of friction between tires and road is μ, what maximum speed can the car have without going into a skid when taking the curve? Express your answer in terms of the variables R, θ, μ and the acceleration due to gravity g. vmax =

Sorry i don’t know what to do

The best answer is (a) which is universal law is in effect at all times. it is constantly at play in everything we do and governs our lives. it is also important to note that universal law applies to not only everything on earth, but everything in the universe as well, which is another reason why it is in effect at all times.

Answerstatic electricity shock;

The figure is missing but we can answer anyway.the correct answer is "releasing the string". in fact, when the person is holding the bow and the arrow, the kinetic energy of the arrow is still zero (because the arrow is not moving). the moment the arrow is released, it acquires a velocity v, so its kinetic energy will become different from zero: where m is the mass of the arrow and v its velocity.  all the other options, instead, do not increase the kinetic energy of the system: -  pulling farther back on the string : this will just increase the elastic potential energy of the system-  holding the arrow higher: this will increase the gravitational potential energy of the system (which is given by u=mgh, where h is the height above the ground)-  decreasing the mass of the arrow: this will decrease the gravitational potential energy of the system (which is given by u=mgh, where m is the mass)