First example: book, m= 0.75 kg, h=1.5 m, g= 9.8 m/s², it has only potential energy Ep,
Ep=m*g*h=0.75*9.8*1.5=11.025 J
Second example: brick, m=2.5 kg, v=10 m/s, h=4 m, it has potential energy Ep and kinetic energy Ek,
E=Ep+Ek=m*g*h + (1/2)*m*v²=98 J + 125 J= 223 J
Third example: ball, m=0.25 kg, v= 10 m/s, it has only kinetic energy Ek
Ek=(1/2)*m*v²=12.5 J.
Fourth example: stone, m=0.7 kg, h=7 m, it has only potential energy Ep,
Ep=m*g*h=0.7*9.8*7=48.02 J
The order of examples starting with the lowest energy:
1. book, 2. ball, 3. stone, 4. brick
Answer:
s = 30330.7 m = 30.33 km
Explanation:
First we need to calculate the speed of sound at the given temperature. For this purpose we use the following formula:
v = v₀√[T/273 k]
where,
v = speed of sound at given temperature = ?
v₀ = speed of sound at 0°C = 331 m/s
T = Given Temperature = 10°C + 273 = 283 k
Therefore,
v = (331 m/s)√[283 k/273 k]
v = 337 m/s
Now, we use the following formula to calculate the distance traveled by sound:
s = vt
where,
s = distance traveled = ?
t = time taken = 90 s
Therefore,
s = (337 m/s)(90 s)
<u>s = 30330.7 m = 30.33 km</u>
Neap tide is when sun and moon are aligned at 90 degrees
spring tide is when sun and moon are in line 180 degrees.
Answer:
No sand doesn't stay sand forever.
Explanation:
- We may have a thought that the sand we see on the beach areas are always the same one for eternal, but it is not true.
- Due to different activities like beach nourishment, sand replenishment etc. the sand in the beach areas are changed and replaced.
- If the sand remained there for long time, it also affects the sand eating organisms and plants.