Given that:
k = 500 n/m,
work (W) = 704 J
spring extension (x) = ?
we know that,
Work = (1/2) k x²
704 = (1/2) × 500 × x²
x = 1.67 m
A spring stretched for 1.67 m distance.
No because light travels in waves and can not stop 3 feet away an having power supplied like that
Answer:

Explanation:
Time can be found by dividing the distance by the speed.

The distance is 45 meters and the speed is 12.5 meters per second.


Divide. Note that the meters, or "m" will cancel each other out.


It will take the dolphin 3.6 seconds to swim a distance of 45 meters are 12.5 meters per second.
Answer:
hence option A is correct
Explanation:
heat required from -9°C to 0°C ice = mass × specific heat of ice ×change in temperature
heat required from -9°C to 0°C ice = 7×2100×9 =132300 J =0.1323 MJ
( HERE SPECIFIC HEAT OF ICE IS A CONSTANT VALUE OF 2100
J/(kg °C )
heat required from 0°C ice to 0°C water = mass× specific heat of fusion of ice
= 7×3.36×10^5
= 2.352 × 10^6 J
= 2.352 MJ
TOTAL HEAT ENERGY REQUIRED = 0.1323 MJ +2.352 MJ
= 2.4843 MJ
hence option A is correct
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