Answer:
Heat flows from hot to cold objects. When a hot and a cold body are in thermal contact, they exchange heat energy until they reach thermal equilibrium, with the hot body cooling down and the cold body warming up. This is a natural phenomenon we experience all the time.
Explanation:
Answer:
i/f = i/o + i/i f = focal, o = object, i = image
1 / i = 1 / f - 1 / o = (o - f) / o f
i = o * f / ( o - f) image distance
i = 12.5 * 22 / (12.5 - 22) = -28.9 cm
Image is real
Image is 28.9 cm to left of lens
M = - i / o = = 28.9 / 12.5 = 2.3 magnification (convex lens)
Answer:
Explanation:
a )
We shall apply the concept of impulse .
Impulse = force x time = change in momentum
= 5 x 4 = 2 ( V - 3 ) , where V is final velocity of the object
20 = 2V - 6
V = 13 m /s
b )
Impulse applied = - 7 x 4 = - 28 kg m/s ( negative as direction of force is opposite motion )
If v be the final velocity
2 x 3 - 28 = 2 v ( initial momentum - change in momentum = final momentum )
- 22 = 2v
v = - 11 m /s
object will move with 11 m /s in opposite direction .
Answer: Option (C) is the correct answer.
Explanation:
As we know that metals are able to conduct electricity so, when a negatively charges rod is kept closer to the left sphere then electrons will enter the sphere.
Since, like charges repel each other. Hence, some of the negative changes from the rod will repel the negative charges of left sphere.
As both left and right spheres are touching each other so, the electrons will move towards the right sphere. As a result, there will be too many electrons (negative charge) present on the right sphere and very less electrons present in the left sphere.
Thus, we can conclude that the statement right sphere is negatively charged, another is charged positively, is true.