Select all that apply.
2 answers:
The correct answer to the question is B) watt and D) joule/sec.
EXPLANATION:
As per the question, the physical quantity given is power.
The power is defined as the rate of consumption of energy or the rate of doing work.
Let us consider W is the amount of work done by a body in time t .
Mathematically the power of that body is written as -
power p =
The unit of work is joule and the unit of time is second.
Hence, the unit of power is joule/sec.
we know that one joule/sec. = one watt.
Hence, watt is also another unit of power.
newton-metre can not be a unit of power . It may be considered as a unit of work.
Similarly H.P/sec is also not a unit of power. Here H.P stands for horse power which is another unit of power .
Hence, joule/sec. and watt are the appropriate units of power.
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Answer:
It would take 16.7 s for the work to be done by the engine.
Explanation:
From the question, given: Power = 390.3 kW
Work to be done = 6.5 x J
But, power and work done with respect to time, has a relationship of:
Power =
So that,
time =
Thus,
time =
= 16.6539
time = 16.7 s
Time required is 16.7 seconds.
Thus, it would take 16.7 s for the work to be done by the engine.
Answer:
a) System aceleration:
b) Direction of movement:
The block down the plane when the acceleration is negative. This occur when:
The block up the plane when the acceleration is positive. This occur when:
Explanation:
For the block the move direction is parallel (||) to the plane
(1)
For the block the move direction is vertical (y)
(2)
Both blocks are connected with the same cable, therefore, the tension on the cable and the acceleration is the same for both.
Solving the equation 2 for T:
(3)
replacing (3) in the equation (1)
(4)
solving (4) for a:
