An object is thrown straight down with an initial speed of 4 m/s from a window which is 8 m above the ground. Calculate: a) The
1 answer:
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Answer:
The final displacement from the origin is <u>1.6</u> km to the <u>NE</u>
Explanation:
The directions in which the delivery truck travels are;
1) 2.8 km North = 2.8·, in vector form
2) 1.0 km East = 1.0·, in vector form
3) 1.6 km South = -1.6·, in vector form
Therefore, to find the final displacement, Δx, of the delivery truck, we add the individual displacements as follows;
Final displacement, Δd = 2.8· + 1.0·
+(-1.6·
) = 1.2·
+ 1.0·
Final displacement, = 1.0· + 1.2·
Where;
Δx = The displacement in the x-direction = 1.0·
Δy = The displacement in the y-direction = 1.2·
The magnitude of the resultant displacement vector is given as follows
= √((Δx)² + (Δy)²) = √(1² + 1.2²) ≈ 1.6 (To the nearest tenth)
The magnitude of the resultant displacement vector ≈ 1.6 km
The direction of the resultant vector is positive for both the east and north direction, therefore, the direction of the resultant vector = NE
Therefore, the resultant displacement of the delivery truck is approximately 1.6 km, NE from the origin.
Answer:
0.273 liters are needed to accomplish this task without boiling.
Explanation:
The minimum boiling point of kerosene is . According to this question, we need to determine the minimum volume of liquid such that heat received is entirely sensible, that is, with no phase change.
If we consider a steady state process and that energy interactions with surrounding are negligible, then we get the following formula by the Principle of Energy Conservation:
(1)
Where:
- Density of kerosene, measured in kilograms per cubic meter.
- Volume of kerosene, measured in cubic meters.
,
- Specific heats of the kerosene and tin, measured in joule per kilogram-Celsius.
,
- Initial temperatures of kerosene and tin, measured in degrees Celsius.
- Final temperatures of the kerosene-tin system, measured in degrees Celsius.
Please notice that the block of tin is cooled at the expense of the temperature of the kerosene until thermal equilibrium is reached.
From (1), we clear the volume of kerosene:
If we know that ,
,
,
,
,
and
, then the volume of the liquid needed to accomplish this task without boiling is:
0.273 liters are needed to accomplish this task without boiling.
A)
The energy of an x-ray photon used for single dental x-rays is
The energy of a photon is related to its wavelength by the equation
where
is the Planck constant
is the speed of light
is the wavelength
Re-arranging the equation for the wavelength, we find
B)
The energy of an x-ray photon used in microtomography is 2.5 times greater than the energy of the photon used in part A), so its energy is
And so, by using the same formula we used in part A), we can calculate the corresponding wavelength: