Answer:
14523.55J
Explanation:
The work done by the jogger against gravity is given by the following equation;
where m is the mass, g is acceleration due to gravity taken as 
and h is the height of the hill.
Since the length of the hill is 132m and it is inclined at 12 degrees to the horizontal, the height is thus given as follows;
Substituting this into equation (1) with all other necessary parameters, we obtain the following;
There are three types of heat conduction through substances. These are named as conduction,convection and radiation .here we have been given convection.
Convection is the type of mode of conduction of heat in which heat will flow though a liquid and gases due to the direct physical movement of particles.In this process the hotter particles will go upward as they become lighter and cooler,heavier particles come downward which after being heated up go upward .Hence a convectional current is formed for which whole of the liquid or gas gets heated.
There are different life examples of convection.
One may take an simple example of water in a container.The water molecules which are present bottom part of the container will be heated up first and go upward.The upper particles will come downward and they will constitute a convectional current.
Another life example is the flow of wind from one region to another region.the air at hotter region will become lighter and goes upward and the wind starts flowing from cold region region in order to occupy the vacant space.
Another example is the hot air balloon rising up..It is also another example of convection of heat
option B open system
because in open system energy and mass can escape from the system or can be added to it.
Answer:
Explanation:
First of all, we have to find the power used by the hair dryer, which is given by
where
V = 120 V is the voltage
is the resistance of the hair dryer
Substituting,
Now we can find the total electrical energy used, given by
where P is the power and
t = 2.5 min = 150 s is the time
Substituting,
