From Alyssa's point of view, the water balloon is at first at rest and then gets thrown with a velocity of 23m/s. Therefore the balloon will have a speed of 23m/s for Alyssa.
At the same time, Naya is watching, and she sees the balloon at the beginning moving at a speed of 14m/s along with Alyssa, and then pushed forward of other 23m/s. Therefore, from her point of view, the balloon will have a speed of 14+23 = 37m/s.
Hence, the correct answer is <span>D) The speed of the balloon is 23 m/s for Alyssa and 37 m/s for Naya.
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Answer:
b)False
Explanation:
This is the false statement .The two forces in each pair could not have different physical origins.
The two pair of forces have same origin.It can not be possible that one is electric force and other one is gravity force or friction force.
We know that magnitude of electric force is much smaller than the friction force .So they can not be in pair form.
Answer is b) False
The 102N acting on the ropes being pulled by eric and kim have some of that force acting horizontally, and some of it vertically. By visualizing it as a right angled triangle, with the hypotenuse the length of the diagonal force, and each side the length of the horizontal and vertical forces, you can use trigonometry to calculate the length of the vertical force. You are told that it is at an angle of 30 with the vertical rope, therefore you know the length of the hypotenuse, and the angle between it and the vertical force, so using trig: (vertical force=x)
x/102=cos(30)
x=102*cos(30)
x=88.33
Therefore the diagonal ropes give a vertical force of 88.33N, and the centre rope, as it acts vertically, gives a vertical force of all 102N. The total:
88.33*2+102=278.66N
I don't know if this is very clear, I hope its good enough to help. If you don't understand, just ask, and I can answer any questions!!! :)
Answer:
Q' = 115.2 KJ
Explanation:
Given that
Current I = 10 A
Voltage = 120 V
Time t= 120 s
The energy supplied Q= V I t
Q= 10 x 120 x 120 J
Q= 144 x 1000 J
Q= 144 KJ
The change in the energy ΔEngg = 28.8 kJ
By using energy conservation
Q= Q' + ΔEngg
Q'=Wasted energy
Now by putting the values in the above equation
144 = Q' + 28.8 KJ
Q' = 115.2 KJ
Therefore the waste energy will be 115 kJ.
