Answer:
Explanation:
b ) The problem is based on Doppler's effect of sound
f = f₀ x (V - v₀) /( 
)
f is apparent frequency ,f₀ is real frequency , V is velocity of sound , v₀ is velocity of observer going away , 
is velocity of source going away
778 = 840 x (340 - 14)/ (340 + )
340 + = 341.18
= 1.18 m /s
it will go away from the observer or the cyclist.
speed of train = 1.18 m /s
a )
For a stationary observer v₀ = 0
f = f₀ x V /( )
= 840 x 340 / (340 + 1.180)
= 837 Hz
The work done in lifting the hamburger is equal to the increase in gravitational potential energy of the hamburger, given by
where
m=0.1 kg is the mass of the hamburger
is the gravitational acceleration
is the increase in height of the hamburger
Substituting numbers into the equation, we find
So, the correct answer is
(3) 0.3 J
Answer:
Generally speaking, scientists have developed four different methods of determining the age of the earth. By using these methods, or a combination of them, the age of geological formations created by past events and even the fossilized bones of prehistoric animals can be determined.
Based on the research done by scientists, the Geologic Column, a graph that illustrates earth age, was developed. The Column, with its names for the epochs and eras of time, illustrates what scientists think was taking place in earth history. A small version of the Geologic Column is pictured at the right.
Explanation:
I hope this helps :)
Answer:
The temperature will decrease (get colder).
Explanation:
Enthalpy changes are heat changes accompanying physical and chemical changes. The enthalpy change is the difference between the sum of the heat contents of products and the sum of heat contents of reactants.
- For an endothermic change, heat is absorbed for the reaction.
- The surrounding becomes colder at the end of the reaction and so is the reaction itself.
- The right choice is that the temperature will decrease.
