Answer:
The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. Although we call them physical "reactions," no reaction is actually occurring. In order for a reaction to take place, there must be a change in the elemental composition of the substance in question. Thus, we shall simply refer to physical "reactions" as physical changes from now on.
Explanation:
Physical changes are limited to changes that result in a difference in display without changing the composition. Some common changes (but not limited to) are:
Texture
Color
Temperature
Shape
Change of State (Boiling Point and Melting Point are significant factors in determining this change.)
Physical properties include many other aspects of a substance. The following are (but not limited to) physical properties.
Luster
Malleability
Ability to be drawn into a thin wire
Density
Viscosity
Solubility
Mass
Volume
Answer:
42 grams
Explanation:
you multiply the value by 1000 to get your answer
V=d/t
V=?
d=400m(4)
=1600m
t=6 min.
=360 s
V=1600m/360s
V=4.4m/s
Answer:
817.5 Pa
Explanation:
From Bernoulli's equation, considering thst there is no height difference then
P1+½d(v1)²=P2+½d(v2)²
P1-P2=½d(v2²-v1²)
∆P=½d(v2²-v1²)
Where P represent pressure, d is density and v is velocity. Subscripts 1 and 2 represent inside and outside. ∆P is tge change in pressure
Given the speed at roof top as 128 km/h, we convert it to m/s as follows
128*1000/3600=35.555555555555=35.56 m/s
Velocity at the bottom of roof is 0 m/s
Density is given as 1.293 kg/m³
∆P=½*1.293*(35.56²-0)=817.5 Pa
Answer:
Width of sound beam is 7.557 m
Explanation:
First we will calculate the wave length from given data:
λ=v/f
Were:
v is the speed
f is the frequency
We considered the opening long and narrow, Using single slit diffraction formula:
mλ=dsinΘ
where:
d is the crack width
m is the order
Θ is angle
Considering m=1, The angle between first minimum from center of beam is:
The width of beam is:
tanΘ=y/L
Width=7.557 m
