Answer:
The initial velocity of the snowball was 22.21 m/s
Explanation:
Since the collision is inelastic, only momentum is conserved. And since the snowball and the box move together after the collision, they have the same final velocity.
Let
be the mass of the ball, and
be its initial velocity; let
be the mass of the box, and
be its velocity; let
be the final velocity after the collision, then according to the law of conservation of momentum:
.
From this we solve for
, the initial velocity of the snowball:

now we plug in the numerical values
,
,
, and
to get:


The initial velocity of the snowball is 22.21 m/s.
<em>P.S: we did not take vectors into account because everything is moving in one direction—towards the west.</em>
Weight = (mass) x (acceleration of gravity at the place where the mass is) .
Man's mass = 80 kg
His weight on Earth = (80 kg) x (9.8 m/s²) = 784 newtons (about 176 pounds)
His weight on the Moon = (80 kg) x (1.63 m/s²) = <em>130.4 newtons</em> (about 29.2 pounds)
His mass is <em>80 kg</em>. Mass is the thing about him that doesn't change.
He has the same mass on the Earth, on the Moon, or anywhere.
It is incorrect, because the identity of the original product has changed. Ca3(OH)2 does not exist! It is no longer calcium hydroxide. To balance an equation, you must manipulate the coefficients, a.k.a. the big numbers that go before reactants or products. Subscripts, the little numbers inside the reactants or products, cannot be changed without completely changing the substance.
The answer is basis of texture
The component of the crate's weight that is parallel to the ramp is the only force that acts in the direction of the crate's displacement. This component has a magnitude of
<em>F</em> = <em>mg</em> sin(20.0°) = (15.0 kg) (9.81 m/s^2) sin(20.0°) ≈ 50.3 N
Then the work done by this force on the crate as it slides down the ramp is
<em>W</em> = <em>F d</em> = (50.3 N) (2.0 m) ≈ 101 J
The work-energy theorem says that the total work done on the crate is equal to the change in its kinetic energy. Since it starts at rest, its initial kinetic energy is 0, so
<em>W</em> = <em>K</em> = 1/2 <em>mv</em> ^2
Solve for <em>v</em> :
<em>v</em> = √(2<em>W</em>/<em>m</em>) = √(2 (101 J) / (2.0 m)) ≈ 10.0 m/s