Answer:
<em>Airbags reduce chances of injury by absorbing most of the impact force from the body during a car crash</em>
Explanation:
In a car collision, the speed of the vehicle is suddenly bought to rest. All the kinetic energy is suddenly converted into other forms of energy.
The body of the driver keeps travelling forward under his inertia force due to his mass until he is slammed against the steering wheel. The steering wheel is a very rigid component, and so when the body slams against it, the body takes the deformation, absorbing some of the energy of the moving car. This sudden impact of energy can be fatal enough to gravely injure the driver because the body does not undergo much deformation. When an airbag is used, the crash automatically triggers the release of the airbag. Instead of the body colliding against the rigid steering wheel, it is now collided against the soft air bag. The airbag is very collapsible, and some of the kinetic energy of the car on the driver is converted into the deformation energy used to deform the airbag when they collide. In the process of deformation, the time of impact is extended, reducing the force impacted on the driver, reducing the fatality of the impact.
Answer:
2.4 × 10 ²¹ N/C
Explanation:
The lead-196 nucleus has 82 proton
Q ( charge on the nucleus ) = 82e where e = 1.602 × 10⁻¹⁹ C
Q = 82 × 1.602 × 10⁻¹⁹ C = 1.314 × 10⁻¹⁷ C
vp ( volume of proton ) = 4/3π r³
V, volume of lead nucleus = 4/3πR³
4/3πR³ = 196 × 4/3π r³
R = ∛(196r³) = 5.81 r = 5.81 × 1.20 ✕ 10⁻¹⁵ m = 6.97 × 10⁻¹⁵ m
magnitude of the electric field = KQ/R² = 8.99 × 10⁹ × 1.314 × 10⁻¹⁷ C / (6.97 × 10⁻¹⁵ m )² = 2.4 × 10 ²¹ N/C
In the photoelectric effect, the energy given by the incoming photon is used partially to extract the electron from the metal (work function) and the rest is converted into kinetic energy of the electron:
where
hf is the energy of the photon, with h being the Planck constant and f the frequency of the photon
is the work function
K is the kinetic energy of the electron
When K=0, we have the minimum energy required to extract the electron from the metal, so the equation becomes
(1)
If we convert the work function of gold into Joules:
We can re-arrange eq.(1) to find the minimum energy of the photon:
Answer:
the pressure exerted by the fluid on its submerged surface
Explanation:
Flotation Force (Archimedes Principle):
If we have a body floating on the surface of a liquid or completely submerged inside it, the resulting force that keeps that body in position is called the "Flotation Force."
When a body is fully submerged in a fluid at rest, the fluid exerts hodrostatic pressure on each of the body parts in contact with the fluid. By the basic equation of the Fluid Static, at the same level h the forces exerted on the body due to the pressure are compensated, since they are equal in magnitude. However, the pressure exerted by the fluid on the lower part of the body will be greater than that exerted on its upper part, so the corresponding forces are different in magnitude and are not compensated. The resulting force due to the difference in hydrostatic pressures between level h2 and level h1 is the buoyant force. That is why this force always acts in a vertical and upward direction. If the floating body does not move, the floating force will be balancing the body weight.
Experimentally it can be verified that the buoyant force does not depend on the material from which the submerged object is made, but on the hydrostatic pressures exerted by the fluid on the volume of said object. That is why we can replace it with the surrounding fluid with its same shape and volume. This portion of fluid will experience the same state of pressures as the body in question.
Answer:
E = 1/2 M V^2 + 1/2 I ω^2 = 1/2 M V^2 + 1/2 I V^2 / R^2
E = 1/2 M V^2 (1 + I / (M R^2))
For a cylinder I = M R^2
For a sphere I = 2/3 M R^2
E(cylinder) = 1 + 1 = 2 omitting the 1/2 M V^2
E(sphere) = 1 + 2/3 = 1.67
E(cylinder) / E(sphere) = 2 / 1.67 = 1.2
The cylinder initially has 1.20 the energy of the sphere
The PE attained is proportional to the initial KE
H(sphere) = 2.87 / 1/2 = 2.40 m since it has less initial KE