Answer:
because all objects fall at a rate of 9.8m/s²
Answer:
V = 49.05 [m/s]
Explanation:
We can easily find the result using kinematics equations, first, we will find the distance traveled during the 5 seconds.

where:
Yo = initial position = 0
y = final position [m]
Vo = initial velocity = 0
t = time = 5 [s]
g = gravity aceleration = 9.81 [m/s^2]
The initial speed is zero, as the body drops without imparting an initial speed. Therefore:
y = 0 + (0*5) + (0.5*9.81*5^2)
y = 122.625[m]
Now using the following equation we can find the speed it reaches during the 5 seconds.
![v_{f} ^{2}= v_{i} ^{2}+(2*g*y)\\v_{f}=\sqrt{2*9.81*122.625} \\v_{f}=49.05 [m/s]](https://tex.z-dn.net/?f=v_%7Bf%7D%20%5E%7B2%7D%3D%20v_%7Bi%7D%20%5E%7B2%7D%2B%282%2Ag%2Ay%29%5C%5Cv_%7Bf%7D%3D%5Csqrt%7B2%2A9.81%2A122.625%7D%20%5C%5Cv_%7Bf%7D%3D49.05%20%5Bm%2Fs%5D)
Momentum = (mass) x (speed)
Mass is constant, so the rate of change of momentum is
(mass) x (rate of change of speed) .
But (rate of change of speed ) is just acceleration.
So the rate of change of momentum is (mass) x (acceleration).
But (mass) x (acceleration) is Force.
So Force is the rate of change of momentum. Verrrrrrrry interesting !
In this problem, Force = (40 kg) x (9 m/s²) = 360 newtons.
One 'Newton' is one kilogram-meter per second² .
Unit of momentum is (kilogram)-(meter per second), so 'newton'
is also a unit of time rate of change of momentum.
Rate of change of momentum is 360 momentum units per second.
Answer:
A. α = 94.4 rad/s
B. a = 28.32 m/s
C. N = 34N
D. α = 94.4 rad/s
a = 28.32 m/s
N = 44.4 N
Explanation:
part A:
using:
∑T = Iα
where T is the torque, I is the moment of inertia and α is the angular momentum.
firt we will find the moment of inertia I as:
I = 
Where M is the mass and R is the radius of the wheel, then:
I = 
I = 0.36 kg*m^2
Replacing on the initial equation and solving for α, we get::
∑T = Iα
Fr = Iα
34 N = 0.36α
α = 94.4 rad/s
part B
we need to use this equation :
a = αr
where a is the aceleration of the cord that has already been pulled off and r is the radius of the wheel, so replacing values, we get:
a = (94.4)(0.3 m)
a = 28.32 m/s
part C
Using the laws of newton, we know that:
N = T
where N is the force that the axle exerts on the wheel part and T is the tension of the cord
so:
N = 34N
part D
The anly answer that change is the answer of the part D, so, aplying laws of newton, it would be:
-Mg + N +T = 0
Then, solving for N, we get:
N = -T+Mg
N = -34 + (8 kg)(9.8)
N = 44.4 N
Answer:
The answer is C. thinking about the smallest particles of matter without experimenting.