Answer:
Explanation:
This is a projectile motion problem. We will first separate the motion into x- and y-components, apply the equations of kinematics separately, then we will combine them to find the initial velocity.
The initial velocity is in the x-direction, and there is no acceleration in the x-direction.
On the other hand, there no initial velocity in the y-component, so the arrow is basically in free-fall.
Applying the equations of kinematics in the x-direction gives
For the y-direction gives
Combining both equation yields the y_component of the final velocity
Since we know the angle between the x- and y-components of the final velocity, which is 180° - 2.8° = 177.2°, we can calculate the initial velocity.
Answer:
I = 0.09[amp] or 90 [milliamps]
Explanation:
To solve this problem we must use ohm's law, which tells us that the voltage is equal to the product of the voltage by the current.
V = I*R
where:
V = voltage [V]
I = current [amp]
R = resistance [ohm]
Now, we replace the values of the first current into the equation
V = 180*10^-3 * R
V = 0.18*R (1)
Then we have that the resistance is doubled so we have this new equation:
V = I*(2R) (2)
The voltage remains constant therefore 1 and 2 are equals and we can obtain the current value.
V = V
0.18*R = I*2*R
I = 0.09[amp] or 90 [milliamps]
Answer: A
Explanation: STEP BY STEP
Answer:
<u>0.04 °C⁻¹</u>
Explanation:
First, we need to calculate linear expansivity, then after finding that value, we can move on to finding the area expansivity.
<u />
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Finding Linear Expansivity :
⇒ α = Final length - Original length / (Original length × ΔT)
⇒ α = 9 - 4 / (4 × 70 - 20)
⇒ α = 5 / 5 × 50
⇒ α = <u>0.02</u>
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Finding Area Expansivity :
⇒ Area Expansivity = 2 × Linear Expansivity
⇒ β = 2 × α
⇒ β = 2 × 0.02
⇒ β = <u>0.04 °C⁻¹</u>
As the length increases, resistance increases, as a result current decreases.
