Answer:
Change, or increase, the buoyant force.
Explanation:
As the salt water of the sea is denser than the river's fresh water, the boat will rise when entering the sea from the river and sink (to increase the buoyant force) when entering the river from the sea.
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Answer: The nearest position of an object from a normal human eye so that its image is formed on retina is 25 CM. If the object is placed at a distance less than 25 CM, then the blurred image of the object is formed on retina as the focal length of a lens cannot be decreased below a certain limit. Hence we cannot see it clearly.
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Answer:
The kinetic energy is: 50[J]
Explanation:
The ball is having a potential energy of 100 [J], therefore
PE = [J]
The elevation is 10 [m], and at this point the ball is having only potential energy, the kinetic energy is zero.
![E_{p} =m*g*h\\where:\\g= gravity[m/s^{2} ]\\m = mass [kg]\\m= \frac{E_{p} }{g*h}\\ m= \frac{100}{9.81*10}\\\\m= 1.01[kg]\\\\](https://tex.z-dn.net/?f=E_%7Bp%7D%20%3Dm%2Ag%2Ah%5C%5Cwhere%3A%5C%5Cg%3D%20gravity%5Bm%2Fs%5E%7B2%7D%20%5D%5C%5Cm%20%3D%20mass%20%5Bkg%5D%5C%5Cm%3D%20%5Cfrac%7BE_%7Bp%7D%20%7D%7Bg%2Ah%7D%5C%5C%20m%3D%20%5Cfrac%7B100%7D%7B9.81%2A10%7D%5C%5C%5C%5Cm%3D%201.01%5Bkg%5D%5C%5C%5C%5C)
In the moment when the ball starts to fall, it will lose potential energy and the potential energy will be transforme in kinetic energy.
When the elevation is 5 [m], we have a potential energy of
![P_{e} =m*g*h\\P_{e} =1.01*9.81*5\\\\P_{e} = 50 [J]\\](https://tex.z-dn.net/?f=P_%7Be%7D%20%3Dm%2Ag%2Ah%5C%5CP_%7Be%7D%20%3D1.01%2A9.81%2A5%5C%5C%5C%5CP_%7Be%7D%20%3D%2050%20%5BJ%5D%5C%5C)
This energy is equal to the kinetic energy, therefore
Ke= 50 [J]
Answer:
position 9.58 m
Explanation:
In impulse exercises and amount of movement, we always assume that the contact time is small,
I = Δp
With this expression we can calculate the final speed
I = m Vf - m Vo
Vf = (I + mVo) / m
Vf = (1.8 + 0.35 1.8) /0.35
Vf = 6.94 m / s
To calculate the acceleration of the ball we use Newton's second law, after finishing the impulse
∑ F = m a
fr = m a
a = fr / m
a = -0.26 / 0.35
a = -0.74 m/s²
A negative sign indicates that this acceleration is slowing the ball
Now we have speed and time acceleration, so we can use the kinematic equations to find the position at 1.5 s
X = Vo t + ½ to t²
In this case Vo is the speed with which the ball comes out after the impulse 6.94
X = 6.94 1.5 + ½ (-0.74) 1.522
X = 9.58 m
Answer: D. All of the choices
