Answer:
15186 J energy lost due to friction
Explanation:
Given:
- Height of the tallest hill (first) h_1 = 16 m
- Height of the last hill h_2 = 7 m
- Velocity @tallest hill = 0
- Velocity @last hill = 0
Find:
How much energy was lost due to friction can be determined from an energy balance at point on top of tallest hill and on top of last hill:
E_p,1 + E_k,1 = E_p,2 + E_k,2 + E_f
Where, E_k,1 = E_k,2 = 0
E_p,1 - E_p,2 = E_f
E_f = m*g*(h_1 - h_2)
E_f = 172*9.81*(16 - 7)
E_f = 15186 J
Answer:
C. How bright it seems to us
Explanation:
Answer:
Explanation:
We start from the ideal conditions previously given, as well
We understand that the formula for Maximum Voltage is given by,
In turn, we can take the expression given for the Instantaneous Voltage, which is defined as,
Replacing all expressions in one,
Eliminating units for better reading
Answer: The elevator must be accelerating.
Explanation:
As the tension force is opposing to the the force of gravity on the load which is hung vertically, and the tension force can adopt any value in order to comply with Newton's 2nd law, if the tension force is less than the force due to gravity, this means that all system is not in equilibrium, so it must be accelerating.
If we assume that the downward is the positive direction, we can write:
mg - T = ma
If T = 0.9 mg, ⇒ mg (1-0.9) =0.1 mg = m a ⇒a = 0.1 g , in downward direction.