Answer:
Explanation:
Given
Sphere of Radius R
Suppose mass of block is m
At any instant \theta Normal reaction(N) and weight(mg) is acting such that
, where v is velocity of block at any angle \theta
When block is just about to leave then N=0
therefore

-------------------1
Also by conserving Energy we get
Potential Energy=kinetic Energy of block

here h=vertical distance traveled by block
From diagram



-----------------2
From 1 and 2



Thus from this value of h is



(a) The efficiency of an engine is defined as the ratio between the work done by the engine and the heat it takes in:

The engine in this problem does a work of

and it takes in

of heat, therefore its efficiency is

(b) The heat taken by the machine is 4000 J; of this amount of heat, only 1100 J are converted into useful work. This means that the rest of the heat is wasted. Therefore, the wasted heat is the difference between the heat in input and the work done by the engine:
Answer:
from hot toward cold. Heat moves naturally by any of three means. The processes are known as conduction, convection, and radiation. Sometimes more than one may occur at the same time.
Explanation:
By Wind
By the Coriolis effect and land
Hope it helped
Answer A material that decreases the rate of a reaction. The amount of energy that reactants must absorb before a chemical reaction will start also called free energy of activation. What role does activation energy pay in chemical reactions? Activation energy is the energy absorbed before it can start a chemical reaction.
Explanation: