I think the correct answer is is D.
Answer:
2, 6
Explanation:
2 because if you cut down more trees you will have less items to help collect co2
6 because if you have more manufracturing more gasses will be release and moe carbon dioxcide in the air so it will slowly kill the ozone layer.
Answer:
<em>60008.4 J</em>
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Explanation:
The mass of each kid = 30 kg
mass of the cart = 20 kg
The speed of the cart down the hill = 30 km/hr = 30 x 1000/3600 = 8.33 m/s
The height of the hill = 80 m
The potential energy of the boys at the top of the hill = mgh
where
m is the total mass of the kids and the cart = (30 x 2) + 20 = 80 kg
g is the acceleration due to gravity = 9.81 m/s^2
h is their height above the ground = 80 m (on the top of the hill)
substituting, we have
potential energy PE = 80 x 9.81 x 80 = 62784 J
At an instance at the bottom of the hill
their kinetic energy = 
where
v is their velocity = 8.33 m/s
m is their total mass = 80 kg
substituting, we have
kinetic energy KE =
= 2775.6 J
Total work done on the cart is equal to the energy lost by the cart when it reached the bottom of the hill
work done by friction = PE - KE = 62784 - 2775.6 = <em>60008.4 J</em>
Answer:
b) The more could in the solenoid of the primary loop of a transformer will induce a greater emf in the secondary loop.
Explanation:
I think what that option was saying was the closer to the magnet the solenoid is, the faster it is going and the greater is the magnetic field due to the magnet in the vicinity of the solenoid, so the emf increases.
refraction is the right answer