Answer:
The position is 8.18cm from the mirror.
Nature is b=virtual
Size is 1.82cm
Explanation:
Note that for a convex mirror, the image distance and the focal length are negative;
Given
Object height H0 = 4cm
object distance u = 18cm
Radius of curvature R = 30cm
Since f = R/2
f = 30/2
f = -15cm
Recall that:
Since the image distance is negative, this shows that the image is a virtual image.
To get the size:
Answer:
F'= 4F/9
Explanation:
Two small objects each with a net charge of +Q exert a force of magnitude F on each other. If r is the distance between them, then the force is given by :
...(1)
Now, if one of the objects with another whose net charge is + 4Q is replaced and also the distance between +Q and +4Q charges is increased 3 times as far apart as they were. New force is given by :
.....(2)
Dividing equation (1) and (2), we get :
Hence, the correct option is (d) i.e. " 4F/9"
Answer:
See the answers below
Explanation:
To solve this problem we must use the definition of power and work in physics.
a)
The function of the conveyor belt is to carry the boxes from an initial point that is at low altitude to an end point that is at high altitude. In this way the conveyor belt prints a speed to the box to be able to raise it to the required vertical distance.
Since we have a velocity at the beginning and then we place the box at a high position, where then the box remains at rest, we can say that it converts kinetic energy to potential energy.
b)
Power is defined as the relationship of work over time. Therefore we have:
where:
P = power = 3.8 [kW] = 3800 [W]
W = work [J]
t = time = 14 [s]
c)
Since the given time is equal to the given time at Point b, we can use the same work calculated.
We know that work is defined as the product of force by the distance traveled.
So, the force is equal to:
Now we know that force is defined as the product of mass by gravitation acceleration.
where:
F = force or weight = 10037.73 [N]
g = gravity acceleration = 9.81 [m/s²]
m = mass [kg]
d)
This part can be solved by means of the energy conservation theorem, where the potential energy is transformed into kinetic energy or vice versa.
where:
h = elevation = 4.7 [m]
v = velocity [m/s]