Answer:
Explanation:
Magnitude of frictional force = μ mg
μ is either static or kinetic friction.
To start the crate moving , static friction is calculated .
a ) To start crate moving , force required = μ mg where μ is coefficient of static friction .
force required =.517 x 56.6 x 9.8 = 286.76 N .
b ) to slide the crate across the dock at a constant speed , force required
= μ mg where μ is coefficient of kinetic friction , where μ is kinetic friction
= .26 x 56.6 x 9.8 = 144.21 N .
Answer:
Three (3).
Explanation:
The octet rule is a rule in chemistry that states that, chemical elements would either gain or loss electrons in their outermost shell in order to attain a stable electronic configuration i.e having eight (8) valence electrons in their outermost shell such as chemical elements found in group 8 (2-8-8) known as noble gas.
A phosphorus atom needs to gain three (3) electrons to achieve a full octet because the atomic number of phosphorus is 15 and as such it has the electronic configuration of 2-8-5 and needs three electron in order to become a stable element.
Answer:
Angle = 0.2520 radians
Explanation:
Complete question:
Sound with frequency 1220Hz leaves a room through a doorway with a width of 1.13m . At what minimum angle relative to the centerline perpendicular to the doorway will someone outside the room hear no sound? Use 344m/s for the speed of sound in air and assume that the source and listener are both far enough from the doorway for Fraunhofer diffraction to apply. You can ignore effects of reflections.
Given Data:
Speed of sound =v= 344 m/sec ;
Width of doorway =d= 1.13m ;
Frequency of sound =f= 1220 Hz ;
Solution:
As we know that
Wvelength = w = v/f = 344/1220 = 0.281967m
Now we also know that
w = dsin(A) where A is the angle
A = arcsin(w/d) =14.44° = 14.44*(3.14/180) = 0.2520 radians
At the angle of 0.252 radians relative to the centreline perpendicular to the doorway a person outside the room will hear no sound under given conditions.
Impuls I is given by:
where
is the change in momentum,
is the average force and t is the time.
Solve the equation for the force F:
Energy should be conserved, so the velocities will be:
Combining both equations:
where
Answer:
It would gain weight
Explanation:
As water only releasing O2 molecules, but intake CO2 and H2O, the combination of molecular mass of CO2 and H2O must be larger than O2 itself. So the overall result is the tree gaining weight at a faster rate that losing weight. Therefore, it would gain more weight as it respires.
