Work = force * distance.
<span>You must produce twice as much energy as we are lifting the weight twice as high. </span>
<span>But because you aren't increasing the force, you need to increase the length of the ramp instead. </span>
<span>The new length will be twice as great as the previous length. </span>
<span>So 8 metres is required. </span>
Hope this helps.
Answer:
I think answer is zero
bcz momentum=mass×velocity
body was initially at rest it means its velocity is zero
30×0=0
When you heat a certain substance with a difference of temperature

the heat (energy) you must give to it is

where

is the specific heat of that substance (given in J/(g*Celsius))
In this case

Observation: the specific heat of a substance is given in J/(g*Celsius) or J/(g*Kelvin) because on the temperature scale a
difference of 1 degree Celsius = 1 degree Kelvin