Answer:
Option (4)
Explanation:
There are two types of collision.
Perfectly elastic collision: the collision in which the momentum and kinetic energy is conserved. There is no loss of energy in other forms of energy.
Perfectly plastic collision: The collision in which the momentum is conserved and kinetic energy is not conserved. The two bodies stick after the collision.
Here, the bullet hits the block and then embedded in the block, it is the example of plastic collision.
Answer:
Decreased by a factor of 4.5
Explanation:
"We have Newton formula for attraction force between 2 objects with mass and a distance between them:
where is the gravitational constant on Earth. are the masses of the object and Earth itself. and R distance between, or the Earth radius.
So when R is tripled and mass is doubled, we have the following ratio of the new gravity over the old ones:
Since and
So gravity would have been decreased by a factor of 4.5
Explanation:
a. Average speed = distance / time
= 100 m / 70 s
= 1.43 m/s
b. Average displacement = displacement / time
= 0 m / 70 s
= 0 m/s
Distance is the length of the path traveled. Displacement is the difference between the final position and initial position.
Answer:
The amount of energy required is
Explanation:
The energy required to convert the ice to steam is the sum of:
1) Energy required to raise the temperature of the ice from -20 to 0 degree Celsius.
2) Latent heat required to convert the ice into water.
3) Energy required to raise the temperature of water from 0 degrees to 100 degrees
4) Latent heat required to convert the water at 100 degrees to steam.
The amount of energy required in each process is as under
1)
where
' is specific heat of ice =
2) Amount of heat required in phase 2 equals
3) The amount of heat required to raise the temperature of water from 0 to 100 degrees centigrade equals
where
' is specific heat of water=
4) Amount of heat required in phase 4 equals
Thus the total heat required equals
1)
The connections between neurons in the retina, specifically the connections referred to as “lateral inhibition,” help us see which of the following better?
<em><u>A) Contrast</u></em>
B) Faces
<span>C) Colors
2)
</span>Improving the contrast of an image (making the dark regions darker and the light regions lighter) helps us to identify:
<em><u>A) The edges of objects</u></em>
B) The center of objects
<span>C) The color of an object
</span>
3)
What assumption does our visual system make in order to see curved surfaces (domes, holes)?
<em><u>A) Light comes from above</u></em>
B) Curved surfaces are always evenly lit
<span>C) Curved surfaces are always easy to see, no assumptions are made
</span>
4)
Which part of the face does our brain pay the most attention to?
<u><em>A) Eyes and mouth</em></u>
B) Eyes and ears
<span>C) Eyes and chin
</span>
5)
If all these assumptions sometimes lead to mistakes, for example in these optical illusions, why do we make them?
A) It helps us see things faster
B) It helps us see things correctly
C) It helps us pay attention to what's important
<span><em><u>D) All of the above
</u></em></span>
Hope that helps :)
*the correct answers are bolded, italicized, and underlined.*