<span>The image formed by a plane mirror is always virtual (meaning that the light rays do not actually come from the image), upright, and of the same shape and size as the object it is reflecting. A virtual image is a copy of an object formed at the location from which the light rays appear to come.</span>
Yes is the answer for you
7. First write down all the known variables while separating the values for each direction:
x-direction:
vix = 20m/s
vfx = 20m/s
x = 39.2m
y-direction:
viy = 0m/s
ay = -9.8m/s^2
y = ?
Based on the knowns, the first step is to calculate the time of flight from the x-direction as it will be the same as value for the y-direction. Find the correct kinematic equation to do so:
x = (1/2)(vix+vfx)t
(39.2) = (1/2)(20+20)t
1.96s = t
Now that we have the time of flight, we can use the kinematic equation that will relate the known variables in the y-direction:
y = viy*t + (1/2)ay*t^2
y = (0)(1.96) + (1/2)(-9.8)(1.96)^2
y = -18.82m (Value is negative because gravity constant was negative. It is the height reference that from the top of the building down, which is why it is negative. The sign can be ignored for this question.)
8. First write down all the known variables while separating the values for each direction:
x-direction:
x = 12m
vfx = 0m/s
vix = ?
y-direction:
y1 = 1.2m
y2 = 0.6m
viy = 0m/s;
ay = -9.8m/s^2
First find time in the y-direction as it would be the same value for the x-direction.
(y2 - y1) = viy*t + (1/2)ay*t^2
(-0.6) = (0)t + (1/2)(-9.8)t^2
t = 0.35s
Now that we have the time of flight, we can use the kinematic equation that will relate the known variables in the x-direction:
x = (1/2)(vix+vfx)t
(12) = (1/2)(vix+(0))(0.35)
68.6m/s = vix
Answer
Give that,
mass of two student m = 3.10 kg
distance from the axis of the rotation is r = 1 m
angular speed ω = 0.754 rad /s
moment of inertia I = 3.10 kg m²
position from the rotation of the axis is r_1 = 0.29 m
Total moment of inertia I ' = I + 2 m r²
= 3.1 +2 x 3.1 x( 1)^2
= 9.3 kg m²
moment of inertia inward horizontally from the position of rotation axis is
I" = I + 2 m r^2
= 3.1 + 2 * 3.1 kg ( 0.29)^2
= 3.62 kg m^2
a ) new angular speed is ω_1 =
= 
= 1.94 rad /s
b ) K.E before the system pulls weight inward is
c )K.E after the system pulls weight inward is
The Earth has cooled for the past 2 million years.
