Explanation:
The runner runs for a total time of
\Delta t=10.0 min= 600 sΔt=10.0min=600s
The energy converted by the runner during this time is equal to the power of the runner times the total time:
E=P \Delta t=400 W \cdot 600 s =2.4 \cdot 10^5 JE=PΔt=400W⋅600s=2.4⋅10
5
J
Since the initial and the final velocity are just equal, it is implied that the acceleration is zero. This means that the net force acting on the body is also zero. The horizontal force should be equal to the force of friction. The force of friction is equal to the product of the coefficient and the normal force.
Ff = (coefficient of friction) x Fn
The normal force is equal to the object's weight if the surface is horizontal.
Ff = (0.20) x (30 kg) x (9.8 m/s²) = 58.8 N
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<span>Thus, the horizontal force exerted must be 58.8 N.
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Answer:
1. Reflection
2. travel from one medium to another
3. Same waves to travel in opposite direction.
Explanation:
1. When a wave strikes a solid barrier, it bounces back in the same medium. This wave behavior of bouncing back is known as reflection. Its like a basketball hitting a backboard. The ball bounces back at the same angle as it was incident. ∠i = ∠r
2. For refraction to occur in a wave, the wave must travel from one medium to another. When light travels from through mediums of different optical densities, it bends. The wave bends away normal when it enters from denser medium to rarer medium. The wave bends towards the normal when it enters from rarer to denser medium. The angle of refraction and angle of incidence are related by Snell's law.

3. The formation of standing wave requires two same waves to travel in the opposite direction and interfere. The incident wave and reflected wave when interfere, form standing waves. There waves are also resonances or harmonics. A standing wave oscillates at one place and does not transfers any energy.
im not sure about most of this but ill try to help
so there are three formulas you need to know first: the formula for rate distance and time.
to find distance:
distance = rate * time
to find time:
time = distance / rate
and to find rate (which is what we need)
rate = distance / time
now we just use our formula and plug in the numbers
rate = distance * time
rate = 160 / 2 = 80
so our rate is 80. thats all i know i have no idea about the rest but i always use these messurments. im sure you can google most of it to get other formulas and calculators though. sorry i couldnt help much! good luck :D
A mechanical wave moves through all matter