A clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light. When we look towards the sun at sunset, we see red and orange colours because the blue light has been scattered out and away from the line of sight.
Explanation:
Given
initial velocity(v_0)=1.72 m/s

using 
Where v=final velocity (Here v=0)
u=initial velocity(1.72 m/s)
a=acceleration 
s=distance traveled

s=0.214 m
(b)time taken to travel 0.214 m
v=u+at


t=0.249 s
(c)Speed of the block at bottom

Here u=0 as it started coming downward

v=1.72 m/s
2.71 m/s fast Hans is moving after the collision.
<u>Explanation</u>:
Given that,
Mass of Jeremy is 120 kg (
)
Speed of Jeremy is 3 m/s (
)
Speed of Jeremy after collision is (
) -2.5 m/s
Mass of Hans is 140 kg (
)
Speed of Hans is -2 m/s (
)
Speed of Hans after collision is (
)
Linear momentum is defined as “mass time’s speed of the vehicle”. Linear momentum before the collision of Jeremy and Hans is
= 
Substitute the given values,
= 120 × 3 + 140 × (-2)
= 360 + (-280)
= 80 kg m/s
Linear momentum after the collision of Jeremy and Hans is
= 
= 120 × (-2.5) + 140 × 
= -300 + 140 × 
We know that conservation of liner momentum,
Linear momentum before the collision = Linear momentum after the collision
80 = -300 + 140 × 
80 + 300 = 140 × 
380 = 140 × 
380/140= 
= 2.71 m/s
2.71 m/s fast Hans is moving after the collision.
Momentum would be the same before and after the collision
Before the collision:
Momentum of the single cart: 1 * 0.50 = 0.50
After the collision
velocity = 0.25m / s
1 * 0.25 + 1 * 0.25 =
0.25 * (1 + 1) =
0.25 * 2 =
0.50
Now new momentum will be 0.5
answer
the same before and after the collision
Answer:
encontré esto fuera de google, "Estos conceptos físicos que parecen necesarios en cualquier teoría física suficientemente amplia son los llamados conceptos físicos fundamentales, una lista no exhaustiva de los mismos podría ser: espacio, tiempo, energía, masa, carga eléctrica, etc."
espero que esto ayude, que tengas un gran día, Y mantente segura! :) :D :3