Answer:

Explanation:
given,
width of door dimension = 1 m
mass of door = 15 Kg
mass of bullet = 10 g = 0.001 Kg
speed of bullet = 400 m/s


a) from conservation of angular momentum





Answer:
1.9 MPa
Explanation:
Mass of person = 81 kg
Mass of chair = 3.8 kg
Diameter of contact point = 1.2 cm = D
Radius of contact point = 1.2/2 = 0.6 cm
Total mass of chair and person = 81 + 3.8 = 84.8 kg = M
Acceleration due to gravity = 9.81 m/s²
Force acting on the floor
<em>F = Mg</em>
<em>⇒F = 84.8×9.81</em>
<em>⇒F = 831.888 N</em>
Area of the contact point
<em>A = πR²</em>
<em>⇒A = π0.006²</em>
<em>⇒A = π0.000036 m²</em>
Area of the four points is
<em>4A = 0.000144π m²</em>
Pressure

Pressure exerted on the floor by each leg of the chair is 1.9 MPa
Explanation:
It is given that,
Mass of the truck, m = 2000 kg
Initial velocity of the truck, u = 34 km/h = 9.44 m/s
Final velocity of the truck, v = 58 km/h = 16.11 m/s
(a) Change in truck's kinetic energy, 



(b) Change in momentum of the truck, 


Hence, this is the required solution.
The answer is 1.99 × 10⁻¹⁰ m.
To calculate this we will use De Broglie wavelength formula:
<span>λ = h/(m*v)
</span><span>λ - the wavelength
</span>h - Plank's constant: h = 6.626 × 10⁻³⁴ Js
v - speed
m - mass
It is given:
<span>λ = ?
</span>m = 9.11 × 10⁻²⁸<span> g
v = </span>3.66 × 10⁶<span> m/s
After replacing in the formula:
</span>λ = h/(m*v) = 6.626 × 10⁻³⁴ /(9.11 × 10⁻²⁸ * 3.66 × 10⁶) = 1.99 × 10⁻¹⁰ m