Answer: Instantaneous speed.
Explanation:
Explanation:
Dark Energy. Dark Energy is a hypothetical form of energy that exerts a negative, repulsive pressure, behaving like the opposite of gravity. It has been hypothesised to account for the observational properties of distant type Ia supernovae, which show the universe going through an accelerated period of expansion
The best option is C. This is due to friction.
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
Answer:
Explanation:
a)Magnitude = 
84=
x= +50.67 or -50.67 units
b) We are given that the resultant is entirely in the -ve x direction which means that the y-component of the resultant is 0; It means that the y-component of the next vector = -ve of the y component of the initial vector i.e 67.
To make the magnitude 80 units in the negative x direction where the y component is 0, the x component must be -130.67(-50.67 - 80) as the x component is + 50.67units.
Magnitude = 
= 146.85 units
c) The direction vector = 67/146.85 i - 130.67/146.85 j where i corresponds to the vector in y direction and j corresponds to the vector in x direction. Or this vector is at an angle of 180 - 
i.e 152.85 degrees from the +ve x-axis.
