Answer:
20.2
Explanation: Divide 726/34 and you get 20.16 round it and you get 20.2
Radiation: Getting sunburnt on a beach.
- The sun’s radiation (no direct contact) is what causes the skin to burn.
Radiation: Microwave cooking food
- Microwaves use radiation to heat the food inside of it; between radio waves and infrared radiation on the electromagnetic spectrum
Conduction: Touching a hot car seat in the summer
- Conduction is the transfer of heat by direct contact (hand to seat).
Conduction: Burning yourself with a curling iron (Similar to above; direct contact).
Convection: An ocean breeze
- Convection near coastlines cause the transfer of energy; water warms and cools slower than land.
Conduction: Sliding down a hot metal slide in august
- You are in direct contact with the slide, which is hot due to the temperature.
Convection: Water in a boiling pot of macaroni
- The water, a liquid, is being heated by molecular motion.
Convection: Currents deep within the earth that cause tectonic plates to move
- Convection currents drive the movement of tectonic plates in the mantle, which is fluid/molten. The currents circulate under the asthenosphere.
<span>The acceleration of the bullet is called ACTION.
</span>Formally stated, Newton's third law<span> is: For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object.
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Answer:
(a) 
(b) 15 hours
Explanation:
half life, T = 12 hours
No = 19 g
(a) Let N be the amount remaining after time t.
Let λ be the decay constant.

The equation of radioactivity used here is given by


(b) N = 8 gram
Substitute the values in above equation

λ = 0.0577 per hour
So, 

Take natural log on both the sides
- 0.0577 t = - 0.865
t = 15 hours