Answer:
42 degrees, virtual image, same size as the object (26 cm)
Explanation:
The law of reflection states that:
- When a ray of light is incident on a flat surface (such as the plane mirror), the angle of reflection is equal to the angle of incidence
So, since in this case the angle of incidence is 42 degrees, the angle of reflection is also 42 degrees.
Moreover, the image formed by a plane mirror is always:
- Virtual (on the same side as the object)
- The same size as the object
So in this case, since the object's size is 26 cm, the image's size is also 26 cm.
Answer:
The value of total energy needed per minute for the humidifier = 77.78 KJ
Explanation:
Total energy per minute the humidifier required = Energy required to heat water to boiling point) + Energy required to convert liquid water into vapor at the boiling point) ----- (1)
Specific heat of water = 4190 
The heat of vaporization is = 2256 
Mass = 0.030 kg
Energy needed to heat water to boiling point = 
Energy needed to heat water to boiling point = 0.030 × 4.19 × (100 - 20)
Energy (
) = 10.08 KJ
Energy needed to convert liquid water into vapor at the boiling point
= 0.030 × 2256 = 67.68 KJ
Thus the total energy needed E =
+ 
E = 10.08 + 67.68
E = 77.78 KJ
This is the value of total energy needed per minute for the humidifier.
Conservation of momentum<span> is a fundamental law of physics. This law states that the </span>momentum<span> of a system is constant if there are </span>no external forces acting on the system. In a situation in which two balls, each with a mass of 0.5 kg, collide on a pool table<span> the law of conservation of momentum is not satisfied because there are external forces that moved the balls. </span>
Answer:
false.
Explanation:
Ok, we define average velocity as the sum of the initial and final velocity divided by two.
Remember that the velocity is a vector, so it has a direction.
Then when she goes from the 1st end to the other, the velocity is positive
When she goes back, the velocity is negative
if both cases the magnitude of the velocity, the speed, is the same, then the average velocity is:
AV = (V + (-V))/2 = 0
While the average speed is the quotient between the total distance traveled (twice the length of the pool) and the time it took to travel it.
So we already can see that the average velocity will not be equal to half of the average speed.
The statement is false
Answer:
b) Momentum decreased
Explanation:
The relative velocity ( with repect to hand) of ball is decreased by moving hand with some velocity in the direction of ball's velocity.