Answer:
<em>The block hits the ground at 27.9 m/s</em>
Explanation:
<u>Gravitational Potential Energy (GPE)</u>
It's the energy stored in an object because of its height in a gravitational field.
It can be calculated with the equation:
U=m.g.h
Where m is the mass of the object, h is the height with respect to a fixed reference, and g is the acceleration of gravity or 
.
When the block is at the edge of the cliff it has potential energy that can be transformed into any other type of energy as it starts falling to the ground.
The GPE of the block of mass m=42 Kg at h=40 m is:
U = 42*9.8*40
U = 16,464 J
The block loses 81 J due to air resistance, thus the energy stored when it hits the ground is 16,464 J - 81 J = 16,383 J.
This energy is stored as kinetic energy, whose formula is:
Solving for v:
v = 27.9 m/s
The block hits the ground at 27.9 m/s
Answer:
difference in flight time= 0.3023 hour
Explanation:
The question is incomplete, but I found it in your textbook.
Spped of aircraft = 850 km/h
Opposing speed of wind = 90km/h
Hence, the net speed when it's travelling west = 850 - 90 = 760 km/hr
The distance covered = 1200km
time taken = distance/ time = 1200/ 760 = 1.5789 hours
When coming back, the speed of the wind is complementary to the speed of the aircraft so
net speed when it's coming back = 850 +90 = 940 km/hr
time taken in this instance = 1200/ 940 = 1.2765 hours
Hence, the difference in flight time= 1.5789 - 1.2765 = 0.3023 hour
Answer:
Explanation:
The current from the battery always flows from the positive terminal of the battery to the negative terminal of the battery.
If we connect a red coloured wire to the positive terminal of the battery and black coloured wire to the negative terminal of the battery, and then reverses the wire to their respective terminals, then there is no change in the direction of flow of current. It does not matter that which wire is connected to the particular terminal. The current always flow from positive to negative terminal of the battery outside the battery.
Answer:
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