Answer:
Molecules speed up
Explanation:
This is caused because of the temperature increasing. The temperature increase is telling us that the thermal energy of the reaction is increasing. When the energy is increased molecules increase their speed, because they have more energy in them
Answer:
It will take 8.80 sec to fall from the building
Explanation:
We have given height pf the state building h = 380 m
Initial velocity will be 0 m /sec
So u = 0 m/sec
Acceleration due to gravity 
We have to find the fall time
According to second equation of motion 
So 

t = 8.80 sec
Option D) A drop of mercury is both a pure substance and and element.
Happy to assist you !
Answer:
Explanation:
net force on the skier = mg sin 39 - μ mg cos39
mg ( sin39 - μ cos39 )
= 73 x 9.8 ( .629 - .116)
= 367 N
impulse = net force x time = change in momentum .
= 367 x 5 = 1835 kg m /s
velocity of the skier after 5 s = 1835 / 73
= 25.13 m /s
b )
net force becomes zero
mg ( sin39 - μ cos39 ) = 0
μ = tan39
= .81
c )
net force becomes zero , so he will continue to go ahead with constant speed of 25.13 m /s
so he will have speed of 25.13 m /s after 5 s .
It’s A.Longitudinal. Tell me if I’m right