We know the equation of motion v = u+ at, where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time taken.
In this case Final velocity = -3.1 m/s, negative sign indicates it is pointing downward.
acceleration = - 3.7m/
. Negative means acceleration is towards center of planet Mars.
Time taken = 3 seconds

So jumping velocity of Julia = 8 m/s
Answer:
C. Takes heat in, does work, and loses energy heat.
Explanation:
Heat engine is a system makes use of thermal energy (heat) to in order to do mechanical work.
This occurs by converting the heat into mechanical energy. This energy is then used to do work.
The key characteristic of a heat engine is that the substance with which work is done by, goes from a higher temperature to a lower temperature.
Hence, it loses heat as it does work.
Kinetic energy = mass time squared speed divided by 2
W=mv^2/2 = 50*10*10/2 = 2500 J
Answer:
d
Explanation:
a and b: it vibrates in both the difference is whether you hear the sound or not the lack or presence of molecules does not hinder the timing fork from vibrating but can hinder you from hearing since sound is a mechanical wave therefore require a medium bringing us to (c) these vibrations are transmitted because there is presence of a medium i.e air molecules so sound can be heard
but in (c) it is true since the vibrations are created but are not transmitted to your ears due to lack of a medium