Why is it not advisable to touch a canvas tent from inside when it is raining?
1 answer:
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Answer:
speed of star is 1.37 × m/s
it is approaching to earth because wavelength of star is decreasing than rest
if emit same wavelength it does not move anywhere
it will remain steady condition with respect earth
Explanation:
given data
wavelength = 656.5 nm
rest wavelength = 656.8 nm
to find out
the speed of the star , is it approaching
solution
we know here equation that is
wavelength shift / wavelength at rest = velocity of source / speed of light
so put all value and find
velocity of source = 3 × × 3 ×
/ 656.8 ×
velocity of source star = 1.37 × m/s
and
it is approaching to earth because wavelength of star is decreasing than rest
and
if emit same wavelength it does not move anywhere
it will remain steady condition with respect earth
When acceleration is constant, the average velocity is given by
where and
are the final and initial velocities, respectively. By definition, we also have that the average velocity is given by
where are the final/initial displacements, and
are the final/initial times, respectively.
Take the car's starting position to be at . Then
So we have
You also could have first found the acceleration using the equation
then solve for via
but that would have involved a bit more work, and it turns out we didn't need to know the precise value of anyway.
Answer:
The acceleration of the crate is 1.8 m/s² so the answer is a.
Explanation:
The very first thing you must do when solving this problem is to draw a free body diagram. (The body diagram is attached to this answer)
So once we got the free body diagram, we can analyze it and build our sum of forces in the x and y directions. Notice that according to the diagram, there are 4 forces to this problem, Normal (N), Weight (W), kinetic friction (fk) and the 750N force.
As one may see in the free body diagram, two of the forces are vertical forces: N and W, so we can use them to build a sum of forces:
Starting with the sum of forces in the y-direction, we get:
Σ=0
We set the sum equal to zero because there is no movement in the y-direction, so the system is in vertical equilibrium.
so the sum will be:
when solving for N we get that:
N=W
where W is found by multiplying the mass of the crate by the acceleration of gravity:
N=250kg*9.8m/s²
N=2450N
Once we found the normal force, we can use it to find the kinetic friction which is given by the following formula:
μ
where μ is the kinetic friction coefficient.
So we get that the kinetic friction is:
so
With this information we can go ahead and find the sum of horizontal forces:
Σ=ma
In this case the sum is equal to mass times acceleration because the crate is moving horizontally due to the action of a force, so it will have an acceleration.
so the sum of forces look like this:
750N-=ma
so
750N-294N=(250kg)a
when solving for a we get:
so the crate's acceleration is 1.82m/s².
