How much work is done on a small car if a 3150 N force is exerted to move it 75.5 m to the side of the road
1 answer:
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Answer:
Approximately .
Explanation:
Let the increase in the rocket's velocity be . Let
represent the initial velocity of the rocket. Note that for this question, the exact value of
doesn't really matter.
The momentum of an object is equal to its mass times its velocity.
- Mass of the rocket with the 5 kg of fuel:
.
- Initial velocity of the rocket and the fuel:
.
- Hence the initial momentum of the rocket:
.
- Mass of the rocket without that 5 kg of fuel:
.
- Final velocity of the rocket:
.
- Hence the final momentum of the rocket:
.
- Mass of the 5 kg of fuel:
.
- Final velocity of the fuel:
(assuming that the the 500 m/s in the question takes the rocket as its reference.)
- Hence the final momentum of the fuel:
.
Momentum is conserved in an isolated system like the rocket and its fuel. That is:
Sum of initial momentum = Sum of final momentum.
.
Note that appears on both sides of the equation. These two terms could hence be eliminated.
.
.
Hence, the velocity of the rocket increased by around 2.5 m/s.
Given:
Height of tank = 8 ft
and we need to pump fuel weighing 52 lb/ to a height of 13 ft above the tank top
Solution:
Total height = 8+13 =21 ft
pumping dist = 21 - y
Area of cross-section = =
=16
Now,
Work done required =
=
= 832)
= 113152 = 355477 ft-lb
Therefore work required to pump the fuel is 355477 ft-lb