Well, when you want to accomplish a goal, you can't take forever to do it now can you? No. The purpose of setting a deadline for your goal is for motivation. You become motivated to do it, instead of putting it off for later. You want to get it done in a reasonable amount of time.
The whistle you use to call has a frequency of 21 kHz, so you do not recognize it also because your threshold of hearing is only 20 kHz. Since you are unable to hear sounds above this value, you request your friend to blow the whistle and move farther away. The frequency will decrease due to Doppler effect.
Answer:
True
Explanation:
Examples of numerical data are height, weight, age
Answer:
It will take 2.68 minutes for them to reach each other.
Explanation:
We use the two following kinematic equations, making the final position the same (for the moment they meet each other):
locomotive 1 --> 
locomotive 2 --> 
we make the two xf equal, and solve for the time (t) using v = 95 km/h:

converting the hours into minutes by multiplying this value times 60;
t = 2.68 minutes
Answer:
15 m/s to the right
Explanation:
Let's say right is positive and left is negative.
Momentum is conserved:
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(6.0 kg) (25.0 m/s) + (15 kg) (0 m/s) = (6.0 kg) (-12.5 m/s) + (15 kg) v₂
v₂ = 15 m/s