Answer:
The magnitude of the acceleration of the elevator is 0.422 m/s²
Explanation:
Lets explain how to solve the problem
Due to Newton's Law ∑ Forces in direction of motion is equal to mass
multiplied by the acceleration
We have here two forces 460 N in direction of motion and the weight
of the person in opposite direction of motion
The weight of the person is his mass multiplied by the acceleration of
gravity
→ W = mg , where m is the mass and g is the acceleration of gravity
→ m = 45 kg and g = 9.8 m/s²
Substitute these values in the rule above
→ W = 45 × 9.8 = 441 N
The scale reads 460 N
→ F = 460 N , W = 441 N , m = 45 kg
→ F - W = ma
→ 460 - 441 = 45 a
→ 19 = 45 a
Divide both sides by 45
→ a = 0.422 m/s²
<em>The magnitude of the acceleration of the elevator is 0.422 m/s²</em>
To solve this problem it is necessary to apply the concepts related to Torque as a function of Force and distance. Basically the torque is located in the forearm and would be determined by the effective perpendicular lever arm and force, that is

Where,
F = Force
r = Distance
Replacing,


The moment of inertia of the boxer's forearm can be calculated from the relation between torque and moment of inertia and angular acceleration

I = Moment of inertia
= Angular acceleration
Replacing with our values we have that



Therefore the value of moment of inertia is 
Answer:
Burning wax
Explanation:
because in burning, wax reacts with oxygen present in the surrounding and forms carbon dioxide and ash
Answer:
ΔT = 59.9 ° C
Explanation:
For this exercise the brake energy is totally converted into heat
Let's calculate the vehicle energy
K = ½ m v²
Let's reduce the units to the SI system
v = 30 mph (1609.34 m / mile) (1h / 3600s) = 13.41 m / s
Em = K = ½ 1200 13.41²
K = 1.079 105 J
All this energy is transformed into heat
Em = Q
The expression for heat is
Q = m
ΔT
ΔT = Q / m
The specific heat of iron is
= 450 J / Kg ºC
ΔT = 1,079 105 / (4.0 450)
ΔT = 59.9 ° C