Answer:
t = 4.468 h
Explanation:
For this exercise let's start by calculating the distance where the boat is
the first trip is 50 miles at 45 °, then 90 miles at 80 °,
to find the total distance let's find the distance of each displacement
cos 45 = x₁ / 50
sin 45 = y₁ / 50
x₁ = 50 cos 45 = 35.35 miles
y₁ = 50 cos 45 = 35.35 miles
cos 80 = x₂ / 90
sin 80 = y₂ / 90
x₂ = 90 cos 80 = 15.63 miles
y₂ = 90 sin 80 = 88.63 miles
let's find the total displacement in each axis
x_total = x₁ + x₂
x_total = 35.35 + 15.63
x_total = 50.98 miles
y_total = y₁ + y₂
y_total = 35.35 + 88.63
y_total = 123.98 miles
Let's use the Pythagorean theorem to find the modulus of the displacement
R = √ (x_total² + y_total²)
R = √ (50.98² + 123.98²)
R = 134.05 miles
The boat goes at a constant speed,
v = R / t
t = R / v
let's calculate
t = 134.05 / 30
t = 4.468 h
Answer:
Consider frames X and Y:
If X sees Y moving to his right then Y must see X moving to his right.
If this is not true then one can choose one frame over the other ( a favored frame and this is not allowed)
Answer:
The current when the filament at room temperature is 11.84 A.
Explanation:
Given that,
Thermal coefficient of resistivity 
Initial temperature = 293 K
Voltage = 140 Volt
Final temperature = 2900 K
Current = 0.95 A
Suppose we find the numerical value of the current when the filament is at room temperature
So, We use the equation of resistance of a material changes with temperature
....(I)
Using ohm's law for value of resistance
Put the value of resistance in the equation (I)
Put the value into the formula
Hence, The current when the filament at room temperature is 11.84 A.
The answer you're looking for is the last option. "ultraviolet radiation." Hope this proves helpful!
Answer:
If you try to lift up a weight in a swimming pool and then try to lift the same weight on the edge of the pool, it feels much lighter in the water.
This was supposed to have been first explained by the Greek scientist Archimedes. He said that the water gives an upward force or upthrust on any object in it.
You can weigh an object in air and then in water and actually work out the upthrust, it is the difference between the two readings. For this reason the upthrust is often called the loss in weight of the object.
