The statement that is true of cooling down after physical activity is that you should cool down for about 5 to 10 minutes after being physically active.
To solve this problem it is necessary to apply the concepts related to the Centrifugal Force and the Gravitational Force. Since there is balance on the body these two Forces will be equal, mathematically they can be expressed as


Where,
m = Mass
G =Gravitational Universal Constant
M = Mass of the Planet
r = Distance/Radius
Re-arrange to find the velocity we have,

At the same time we know that the period is equivalent in terms of the linear velocity to,


If our values are that the radius of mars is 3400 km and the distance above the planet is 100km more, i.e, 3500km we have,



Replacing we have,



Therefore the correct answer is C.
Answer:
t=18s
Explanation:
The final position of an object moving at constant speed is given by the formula
, where
is its initial position, v its speed and t the time elapsed.
For the cheetah we have
, and for the gazelle
. We want to know at which t their positions are equal, that is,
, which means,

Where we can do:



We then substitute the values we have (the initial position of the cheetah is 0m), writing the meters in km so distance units cancel out correctly:

On the last step we just multiply by 3600 because is the number of seconds in an hour.
For this
specific problem, the maximum value for d is 52m. I am hoping
that this answer has satisfied your query about and it will be able to help
you, and if you’d like, feel free to ask another question.
Answer:
e).
Explanation:
Assuming no external forces acting during the instant of the explosion, total momentum must be conserved.
As the object was initially at rest, the initial momentum is zero, which means that after the explosion, total momentum must add to zero too.
Let's call m₁ = 3 kg-piece and m₂= 6 kg-piece.
⇒ m₁*v₁ + m₂*v₂ = 0
⇒ 3kg* v₁ = -6kg*v₂
⇒ 6/3 = 2 = v₁/v₂ ⇒ v₂/v₁ = 1/2 (in magnitude)
v₂ (being the speed of the 6-kg piece) = 1/2 * v₁ (speed of thr 3-kg piece).
So, we conclude in that the statement e) is the one that is true.