Friction = 0.25 * m * g = 10.8
Push = m * a + Friction = 4.4 * 1.5 + 10.8
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)
To solve this problem, we can use the cosine formula for
calculating the length of the displacement:
c^2 = a^2 + b^2 – 2 a b cos θ
where c is the displacement, a = 3.5 km, b = 4.5 km, and θ
is the angle inside the triangle
Since the geeze turned 40° from west to north, so the
angle inside the triangle must be:
θ = 180 – 40 = 140°
c^2 = 3.5^2 + 4.5^2 – 2 (3.5) (4.5) cos 140
c^2 = 56.63
c = 7.53 km
<span>So the magnitude of the displacement is 7.53 km</span>
Answer:
a. I = 30 A
b. E = 1080000 J = 1080 KJ
c. ΔT = 12.86°C
d. Cost = $ 4.32
Explanation:
a.
The current in the coil is given by Ohm's Law:

where,
I = current = ?
V = Voltage = 120 V
R = Resistance = 4 Ω
Therefore,

<u>I = 30 A</u>
<u></u>
b.
The energy can be calculated as:

<u>E = 1080000 J = 1080 KJ</u>
<u></u>
c.
For the increase in the temperature of water:

where,
m = mass of water = 20 kg
C = specific heat of water = 4.2 KJ/kg.°C
Therefore,

<u>ΔT = 12.86°C</u>
<u></u>
d.
First, we will calculate the total energy consumed:

Now, for the cost:

<u>Cost = $ 4.32</u>
Explanation:
C,
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