Complete Question
While john is traveling along a straight in interstate highway, he notices that the mile marker reads 242 km. John travels until he reaches the 147 km marker and then retraces his path to the 161 km marker. What is John's resultant displacement from the 242 km marker? How far has he traveled answer in units of km
Answer:
The resultant displacement 
The total distance traveled by john is 
Explanation:
From the question we are told that
The first position of john from the finish point is 
The second position of john from the finish point is 
The third position of john from the finish point is 
Generally the displacement from the 242 km marker is mathematically represented as
Here we used 
instead of 
because is further than from the finish point
=>
Generally the total distance traveled by John is mathematically evaluated as
![x_t = [x_1 - x_2 ] + [x_3 - x_2]](https://tex.z-dn.net/?f=x_t%20%3D%20%20%5Bx_1%20-%20x_2%20%5D%20%2B%20%5Bx_3%20-%20x_2%5D)
=> ![x_t = [242 - 147 ] + [161 - 147]](https://tex.z-dn.net/?f=x_t%20%3D%20%20%5B242%20%20-%20147%20%5D%20%2B%20%5B161%20-%20147%5D)
=>
<span>In this case we are given a force of 29,000 N. We know
that the equation we can use is:</span>
Force = mass * acceleration
However this is not just any type of force, because this
is the weight of the elevator. So when the force is equal to weight, the
acceleration acting is simply gravity. Therefore:
weight = mass * gravity
Calculating for mass:
mass = 29,000 N / (9.8 m/s^2)
<span>mass = 2,959.18 kg</span>
Answer:
Rate of energy loss by radiation is 28.31 Watt
Explanation:
Given that;
m = 30 kg
power p = 12 W
emissivity e = 0.97
Surface Area A = 0.56 m²
outside of the penguin's body T = −22°C
surroundings Temperature Ts = -38°C
the rate of energy loss by radiation = ?
Now, using Stefan-Boltzmann law;
P = σeA [ T⁴ - Ts⁴ ]
Stefan's constant σ = 5.67 × 10⁻⁸
so we substitute
P = 5.67 × 10⁻⁸ × 0.97 × 0.56 [ (-22 + 273 k)⁴ - (-38 + 273 k )⁴]
= 3.079944 × 10⁻⁸ [ 919325376]
= 28.31 Watt
the rate of energy loss by radiation is 28.31 Watt
To write it in the form ai + bj, we need to find a and b
which are:
a = x component
b = y component
length of x = 9 – 2 = 7
length of y = 25 – 1 = 24
tan θ = 24 / 7
θ = 73.74°
a = (50 m/s) cos 73.74
a = 14 m/s
b = (50 m/s) sin 73.74
b = 48 m/s
Hence,
14i + 48j
