You can use Vf^2-Vi^2 = 2ax
Vf^2 - 0 = 2(9.81)(25)
Or you can use energy
mgh = 1/2mv^2
2gh =v^2
Same thing
Answer:
Time period of the osculation will be 2.1371 sec
Explanation:
We have given mass m = (B+25)
And the spring is stretched by (8.5 A )
Here A = 13 and B = 427
So mass m = 427+25 = 452 gram = 0.452 kg
Spring stretched x= 8.5×13 = 110.5 cm
As there is additional streching of spring by 3 cm
So new x = 110.5+3 = 113.5 = 1.135 m
Now we know that force is given by F = mg
And we also know that F = Kx
So 

Now we know that 
So 


Answer:
Position =
behind the mirror
Nature = Virtual and Erect
Size =
: Diminished
Explanation:
Sign convention-Distance measured to the left of pole is negative and to the right of pole is positive.
Object distance = u = -20 cm
Focal length = f = Radius of curvature/2 = 30/2 = 15 cm
We have to use mirror formula to find image distance.

Since the image distance is positive, it is formed behind the mirror or a virtual image is formed.
Magnification = 

Height of the object = 5 cm
Height of the image = 
Since the height of the image is positive and less than the size of object,it is erect and diminished.
KE = 1/2 * m * v2
We have to rearrange this so the subject is mass. (because the question asks for the mass of the object) :
Mass = (2 * KE) / v
Now input the values into this equation to get your answer :
Mass = (2 * KE) / v
Mass = (2 * 480) / 8
Mass = 960 / 8
Mass = 120