Heated air rises while cooled air sinks.
Answer: The answer is A
Explanation: The bumper is the first part of an automobile to be impacted when in a head-on accident
<u>Answer:</u>
The final velocity of the two railroad cars is 1.09 m/s
<u>Explanation:</u>
Since we are given that the two cars lock together it shows that the collision is inelastic in nature. The final velocity due to inelastic collision is given by

where
V= Final velocity
M1= mass of the first object in kgs = 12000
M2= mas of the second object in kgs = 10000
V1= initial velocity of the first object in m/s = 2m/s
V2= initial velocity of the second object in m/s = 0 (given at rest)
Substituting the given values in the formula we get
V = 2×12000 + 0x100012000 + 10000= 2400022000= 1.09 m/s

Which is the final velocity of the two railroad cars
Answer:
c = 894.90 m/s
Explanation:
Given data:
Frequency of wave = 471 Hz
Wavelength of wave = 1.9 m
Speed of wave = ?
Solution:
Formula:
Speed of wave = frequency × wavelength
c = f×λ
c = 471 Hz × 1.9 m
Hz = s⁻¹
c = 471s⁻¹ × 1.9 m
c = 894.90 m/s
The speed of wave is 894.90 m/s.