K.E. = 1/2 mv²
K.E. is directly proportional to v^2
So, when K.E. increase by 2, K.E. increase by root. 2
v' = 1.41v
original v value was 3 so, final would be:
v' = 1.41*3 = 4.23
After round-off to it's tenth value, it will be:
v' = 4.2
So, option B is your answer!
Hope this helps!
Answer:
Net pull = 110 N to the left
Explanation:
Group the different pulls according to the direction (right or left)
2 pull 196 N each to the right
4 pull 98 N each to the left
5 pull 62 N each to the left
3 pull 150 N each to the right
1 pull 250 N to the left
Since positive direction is to the right, the pulls to the left will have a minus (-)

The resulting force is negative, meaning the direction is to the left
A star chart<span> or </span>star map<span> is a </span>map<span> of the night </span>sky <span>Astronomers divide these into grids to use them more easil They are used to identify and locate astronomical objects such as stars constellations and galaxie it is in my text book </span>
Efficiency = Power Output / Power Input
Power Input = Rate of Energy input = 44.4 MJ/kg * 5 kg/h
= 222 MJ/h
But 1 hour = 3600seconds
222 MJ/h = 222 MJ/3600s = 0.061667 MW J/s = Watts
Power input = 0.061667 MW = 61 667 W
From Efficiency = Power Output / Power Input
28% = Power Output / 61667
Power Output = 0.28 * 61667
Power Output = 17266.76 W
Power Output ≈ 17 267 W
Rate of heat rejection = Power Input - Power Output
= 61667 - 17267 = 44400 W
Rate of heat rejection = 44 400W.