Atmospheric pressure is caused by the weight of the atmosphere pushing down on itself and on the surface below it.
Pressure is defined as the force acting on an object divided by the area upon witch the force is acting.
Answer:
4.2591 cm
Explanation:
We have given focal length of the lens f=6.91 cm
Object distance u =11.1 cm
We have to find the image distance that is v
For the lens we know that
So
Answer:
Positive
Explanation:
Work is defined as the product of displacement of an object produced by the applied force and the component of force along that direction. Let us consider a situation in which the angle between the applied force and the displacement produced by it is at an angle θ. Let the magnitude of displacement be s and that of the applied force be F. Now, we have to find the component of force along the direction of the displacement. For that we have to resolve the force in to two components- one along the direction of displacement and other perpendicular to it. Since the angle between force and displacement is θ, the component of force along the direction of displacement will be Fcosθ and that perpendicular to it will be Fsinθ. Thus, b the definition of work, work done = Fcosθ x s = Fscosθ.
Now, coming to our question, the force here is gravitational force of attraction which is along downward direction. It is given in the question itself that the stone is falling down. Since the displacement and the applied force is along the same direction, angle between them, θ = 0.
Thus, work done = Fscosθ = Fscos0 = Fs (since cos0 =1)
Fs > 0
Thus, the work done is positive
The answer would be B the method of rock formation
Answer:
The resistance of the silicon has to be 80 Ω and the iron must be 1120 Ω
Explanation:
Lets take
Temperature coefficients of resistivities or iron =
Temperature coefficients of resistivities or silicon =
The resistance of the iron increases a little as the temperature rises
The resistance of the silicon decreases a lot as the temp rises.
So we want the iron to be most of the resistance and have its increase in resistance exactly equal to the drop in resistance of the silicon.
Since the drop in the silicon is 15 times the rise in the iron ( 75 / 5 ) you want the iron to have 15 time the resistance of the silicon. And the total resistance has to be 1200Ω
1200/15 = 80
So
The resistance of the silicon has to be 80 Ω and the iron must be 1120 Ω