Answer:
The universal sign for choking is __________.
A.
two balled fists pressing the abdomen
B.
pointing at an open mouth
C.
two hands grasping the neck
D.
pretending to cough
Explanation:
Answer:
and 
Explanation:
The wavelength of a visible light is 727.3 nm.

The formula is as follows :

f is the frequency of the visible light

Energy of a photon is given by :
E = hf, h is Planck's constant

Red color has a frequency of
and energy per photon is
.
Answer:
v=9.6 km/s
Explanation:
Given that
The mass of the car = m
The mass of the truck = 4 m
The velocity of the truck ,u= 12 km/s
The final velocity when they stick = v
If there is no any external force on the system then the total linear momentum of the system will be conserve.
Pi = Pf
m x 0 + 4 m x 12 = (m + 4 m) x v
0 + 48 m = 5 m v
5 v = 48

v=9.6 km/s
Therefore the final velocity will be 9.6 km/s.
At 0 Kelvin everything stops moving ( even electrons ), so you could try to decrease the system's temperature
0 Kelvin = -273 Celsius
Answer:
Work Function = 3.53 x 10⁻¹⁹ J = 2.2 eV
Explanation:
The work function of the metal metal can be found as follows:
Energy of Photon = Work Function + K.E
hc/λ = Work Function + K.E
Work Function = hc/λ - K.E
where,
h = Plank's Constant = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of photons = 240 nm = 2.4 x 10⁻⁷ m
K.E = Maximum Kinetic Energy = (2.97 eV)(1.6 x 10⁻¹⁹ J/1 eV) = 4.752 x 10⁻¹⁹ J
Therefore,
Work Function = (6.625 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(2.4 x 10⁻⁷ m) - 4.752 x 10⁻¹⁹ J
Work Function = 8.281 x 10⁻¹⁹ J - 4.752 x 10⁻¹⁹ J
<u>Work Function = 3.53 x 10⁻¹⁹ J = 2.2 eV</u>