Asled of mass m starts from rest at the top of a hemispherical frictionless hill of radius r.

a) use conservation of mechanical energy to find an expression for the sled’s speed when it is at an angle ∅.
b) use newton’s 2nd law and ideas of circular motion to find the maximum speed the sled can have at angle without leaving the surface.
c) at what angle ∅_max does the sled "fly off" the hill?

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.

Click the game tab at the bottom of the simulation and select level 1. (there is no seesaw balance for this part of the activity.) balance the first equation, and click check to see if you got it right. if you can’t balance it in the first try, you can try again. work through the five equations for level 1. click continue to go on to level 2, and later level 3. each level is more difficult than the one before. keep trying until all the equations are balanced. in one or two sentences, describe how you did in the balancing game. in a few more sentences, explain one strategy you learned for balancing more complex equations.

70 give a real life example showing how sensory neurons work with the motor neurons