5.5 s
Explanation:
The time it takes for the ball to reach its maximum height can be calculated using
since 
at the top of its trajectory. Plugging in the numbers,
Answer:
second one is correct that is right
Answer:
C.) The amount of mass used up in holding a nucleus together.
Explanation:
The mass defect of a nucleus represents the mass of the energy binding the nucleus. It is the difference between the mass of the nucleus and the sum of the masses of the nucleons of which it is composed.
Regards!
In this item, we let x be the rate of the boat in still water and y be the rate of the current.
Upstream. When the boat is going upstream, the speed in still water is deducted by the speed of the current because the boat goes against the water. The distance covered is calculated by multiplying the number of hours and the speed.
(x - y)(3) = 144
Downstream. The speed of the boat going downstream is equal to x + y because the boat goes with the current.
(x + y)(2) = 144
The system of linear equations we can use to solve for x is,
3x - 3y = 144
2x + 2y = 144
We use either elimination or substitution.
We solve for the y of the first equation in terms of x,
y = -(144 - 3x)/3
Substitute this to the second equation,
2x + 2(-1)(144 - 3x)/3 = 144
The value of x from the equation is 60
<em>ANSWER: 60 km/h</em>
