Explanation:
Fgravity = G*(mass1*mass2)/D².
G is the gravitational constant, which has the same value throughout our universe.
D is the distance between the objects.
so, if you triple one of the masses, what does that do to our equation ?
Fgravitynew = G*(3*mass1*mass2)/D²
due to the commutative property of multiplication
Fgravitynew = 3* G*(mass1*mass2)/D² = 3* Fgravity
so, the right answer is 3×12 = 36 units.
Ok so the expression that you will be doing is water-water+object. The actual expression is 120-80. The answer would be 40mL. Remember, don't forget your units! :)
Look at the title of the graph, in small print under it.
Each point is "compared to 1950-1980 baseline". So the set of data for those years is being compared to itself. No wonder it matches up pretty close !
a) 0.94 m
The work done by the snow to decelerate the paratrooper is equal to the change in kinetic energy of the man:

where:
is the force applied by the snow
d is the displacement of the man in the snow, so it is the depth of the snow that stopped him
m = 68 kg is the man's mass
v = 0 is the final speed of the man
u = 55 m/s is the initial speed of the man (when it touches the ground)
and where the negative sign in the work is due to the fact that the force exerted by the snow on the man (upward) is opposite to the displacement of the man (downward)
Solving the equation for d, we find:

b) -3740 kg m/s
The magnitude of the impulse exerted by the snow on the man is equal to the variation of momentum of the man:

where
m = 68 kg is the mass of the man
is the change in velocity of the man
Substituting,
