Answer:
0.2s
force = change in momentum/ time
time = change in momentum/time
Explanation:
first, let's find the change in momentum
pf-pi
5×(-2) - 5× 2
-20kgm/s = 20kgm/s(by changing the direction of whole system)
time = change in momentum/time
20/100
<u> 0.2s</u>
Answer:
The rocket has to be launched 8 m from the hoop
Explanation:
Let's analyze this problem, the rocket is on a car that moves horizontally, so the rocket also has the same speed as the car; The initial horizontal rocket speed is (v₀ₓ = 3.0 m/s).
On the other hand, when starting the engines we have a vertical force, which creates an acceleration in the vertical axis, let's use Newton's second law to find this vertical acceleration
F -W = m a
a = (F-mg) / m
a = F/m -g
a = 7.0/0.500 - 9.8
a = 4.2 m/s²
We see that we have a positive acceleration and that is what we are going to use in the parabolic motion equations
Let's look for the time it takes for the rocket to reach the height (y = 15m) of the hoop, when the rocket fires its initial vertical velocity is zero (I'm going = 0)
y = 
t + ½ a t²
y = 0 + ½ a t²
t = √ 2y/a
t = √( 2 15 / 4.2)
t = 2.67 s
This time is also the one that takes in the horizontal movement, let's calculate how far it travels
x = v₀ₓ t
x = 3 2.67
x = 8 m
The rocket has to be launched 8 m from the hoop
Answer:
w = 0.55 rad / s
Explanation:
For this exercise let's use the conservation of angular momentum, let's write the moment in two moments
Initial
L₀ = r p + 0
L₀ = r mv
The first term is the angular momentum of the mass
Final
Lf = (I + m r²) w
Where I is the moment of inertia of the stool and the other term is the moment of inertia of the mass
L₀ = Lf
r mv = (I + m r²) w
w = m r v / (I + m r²)
Let's calculate
w = 2.0 0.45 3.0 / (4.5 + 2.0 0.45²)
w = 2.7 / 4.9
w = 0.55 rad / s
<span>Transmission electron microscope -
The transmission electron microscope uses electrons instead of light
. a light microscope is limited by the wavelength of light.
TEMs use electrons as "light source" and their much lower wavelength makes it possible to get a resolution a thousand times better than with a light microscope
.
The possibility for high magnifications has made the TEM a valuable tool in both medical, biological and materials research.</span><span>Compound light microscope
- Microscope with more than one lens and its own light source
. There are ocular lenses in the bonicular eyepieces and objective lenses in a rotating nosepiece closer to the specimen.
To ascertain the power of magnification of a compund light microscope, it's needed to take the power of the objective lens and multiply it by the eyepiece which is generally 10x.
Although sometimes found as monocular with one ocular lens, the compound binocular microscope is more commonly used today.
The first light microscope dates back to 1595, when Zacharias Jansen created a compound microscope that used collapsing tubes and produced magnifications up to 9X.
</span>
The last picture represents a pure compound
