It is the very last answer
Physical change = changes the physical properties (more commonly known as it's look)
Chemical change = changes the chemical properties into an entire new chemical form
Examples of physical change would be melting ice cubes or sugar cubes.
Examples of chemical change would be cooking eggs or burning paper because you're changing its chemical properties.
Answer:
7.53 km
Explanation:
We at given;
Speed of runner; v_r = 8.5 km/hr
Speed of bird; v_y = 17 km/hr
L = 6.4 km
We know that; time = distance/speed.
We are told that the bird starts from 6.4 km from the start and that it flies back to meet the runner after it reaches the finish line. If the total distance back to the runner is x, it means bird distance is 6.4 + (6.4 - x) = 12.8 - x
Thus;
Time of bird(t_y) = (12.8 - x)/17
Thus,
Time of runner(t_r) = x/8.5 hr
To find x, we have to equate the times of the runner and the bird.
Thus;
x/8.5 = (12.8 - x)/17
Multiply both sides by 17 to get;
2x = 12.8 - x
2x + x = 12.8
3x = 12.8
x = 12.8/3
x = 4.27 km
Thus, cumulative distance traveled by bird is; 12.8 - 4.27 = 7.53 km
Answer:
1. 
2. 
3. 
Explanation:
Use conservation of momentum:
1.
The expression for the magnitude of the BB's velocity is
v2i = 0 m/s, solve for v1f
2.
Now replacing numeric to find the value
3.
Now is doesn't exist the box the velocity will be
v1f = v2f = vf
Conservation of Momentum
