Ek = 6KJ.
In physics, the kinetic energy of a body or object is the one that owns due to its movement and is given by the equation
, where m is the mass of the object in kilograms and v is the velocity in m/s.
An object that it has a mass of 30 kilograms and moves with a velocity of 20m/s, its kinetic energy is given by:

In order to build a hypothesis, Joan should take an educated guess at what the effect of adding salt to the water will be on the water's boiling point. For example, the hypothesis may be,"The boiling point will increase". This hypothesis is one that can be verified or rejected via experimentation. The next step for Joan would be to set up an experiment to test this hypothesis.
<span>The total amount of kinetic energy and potential energy within a system is called "Mechanical Energy"
In short, Your Answer would be Option C
Hope this helps!</span>
(since you asked for basic understanding only, I am not including actual calculations. Please let me know in the comments section if you wish to verify your solution(s))
For (b): Use the formula for distance (s) made during an accelerated motion:

with v_0 and s_0 being the initial velocity and distance, both 0 in this case, and with "a" denoting the acceleration, in this case solely due to gravitational acceleration so: "g."
You are given the distance made, namely 10 m, and the duration t (0.88s) and so using the formula above you can solve for g.
For (c), to determine the final velocity at time 0.88s use the formula for the instantaneous velocity of an accelerated motion
(velocity at time t) = (acceleration) x (time)
again, with acceleration due to gravity, i.e., a = g and with g as determined under (b).
If my calculation is correct, this mystery planet could be the Jupiter.
Answer:
Δt=0.85 seconds
Explanation:
In this chase the speed does not change as the mass change.So we can use the follow equation to find the required time
Δt=Δv/gμ
To stop the final speed will be zero therefore the change in speed will be
Δv= vf-vi
Δv=0-5 m/s
Δv= -5 m/s
Now we plug our values for Δv,g and μ to find time
Δt=Δv/gμ
Δt=(-5m/s) ÷(9.8m/s² × 0.6)
Δt=0.85 seconds