Answer: 2 cm
Explanation:
Given , for a converging lens
Focal length : 
Height of object : 
Object distabce from lens : 
Using lens formula:
, we get
, where v = image distance from the lens.
On solving aboive equation , we get

Formula of Magnification :
, where h' is the height of image.
Put value of u, v and h in it , we get

Hence, the height of the image is 2 cm.
Answer:
2 moles
Explanation:
2 moles becz
1 mole of oxygen = 16
.: 2 moles of oxygen = 36
:)
Answer: 4
Explanation: speed= distance/time
Answer: gravitational potential energy is converted into kinetic energy
Explanation:
When the diver stands on the platform, at 20 m above the surface of the water, he has some gravitational potential energy, which is given by

where m is the man's mass, g is the gravitational acceleration and h is the height above the water. As he jumps, the gravitational potential energy starts decreasing, because its height h above the water decreases, and he acquires kinetic energy, which is given by

where v is the speed of the diver, which is increasing. When he touches the water, all the initial gravitational potential energy has been converted into kinetic energy.
Complete Question
The complete question is shown on the first and second uploaded image
Answer:
The velocity is
Explanation:
The kinetic energy of the 9 kg can be determined by these expression
Kinetic energy of 9 kg block = initial energy stored - energy lost as a result of friction
Now to obtain the initial energy stored
Let U denote the initial energy stored and

Where x is the length the spring is displaced
k is the force constant of the string


Now referring to the formula above
i.e Kinetic energy of 9 kg block = initial energy stored - energy lost as a result of friction



and we are told that coefficient of friction = 0.4 and the mass is 9 kg ,the acceleration due to gravity
this displacement length of spring = 0.6
Therefore 