Answer: 90.1 s
Explanation:
Use equation for power:
P=F*V
Use eqation for force:
F=ma
F---force
V---velocity
Vr=om/s
V=30m/s
m=1000kg
P=10000W
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P=FV
F=P/V
F=10000W/30m/s
F=333.33N
Use equation for force to find accelartaion.
F=ma
a=F/m
a=333.33N/1000kg
a=0.333 m/s²
Use equation for accelaration to find out time:
a=(V-Vs)/t
t=(V-Vs)/a
t=(30m/s)/(0.333m/s²)
t=90.09 s≈90.1 s
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1. False
2.False
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5. True
6. False
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9. True
10. False
Answer:
Explanation:bjbhfcvvjkkknbnnnm
A. A stretched catapult can do work when released so it must have potential energy.
b. A stone on the ground will not move on its own ever again so it has zero energy.
c. In order to roll an object there must be a friction force between the object and the ground (otherwise it will slide)
d. To lift a stone you must overcome the weight which is the force due to gravity.
e. Work and energy are both measured in Joules.
Answer:
a) 0.15 μC b) 9.4*10¹¹ electrons.
Explanation:
As the total charge must be conserved, the total charge on the spheres, after being brought to contact each other, and then separated, must be equal to the total charge present in the spheres prior to be put in contact:
Q = +8.2μC +9.0 μC +(-7.8 μC) + (-8.8 μC) = +0.6 μC
As the spheres are assumed perfect conductors, as they are identical, once in contact each other, the excess charge spreads evenly on each sphere, so the final charge, on each of them, is just the fourth part of the total charge:
Qs = Qt/4 = 0.6 μC / 4 = 0.15 μC.
b) As the charge has a positive sign, this means that each sphere has a defect of electrons.
In order to know how many electrons are absent in each sphere, we can divide the total charge by the charge of one electron, which is the elementary charge e, as follows: