Answer:
The power of the corrective lenses is 3.162 D.
Explanation:
Given that,
Object distance = 70 cm
Image distance = 62 cm
Distance between eyes and glasses = 2.5 cm
Eyeglasses made of diverging corrective lenses can help her to see the apple clearly
So now ,
Object distance from glass =70-2.5 = 67.5 cm
Image distance from glass = 62-2.5 = 59.5 cm
We need to calculate the focal length
Using formula for focal length



We need to calculate the power of lens
Using formula of power



Negative sign shows the lens is diverging.
Hence, The power of the corrective lenses is 3.162 D.
Answer:
h = 22.35 m
Explanation:
given,
initial speed of the rock,u = 0 m/s
length of the window,l = 2.7 m
time taken to cross the window,t = 0.129 s
Speed of the rock when it crosses the window


v = 20.93 m/s
height of the building above the window
using equation of motion
v² = u² + 2 g h
20.93² = 0² + 2 x 9.8 x h
h = 22.35 m
Hence, the height of the building above the top of window is equal to h = 22.35 m
Answer:
A bicycle on the top of the hill has the highest potential energy, and when the bike goes down, it transfers to kinetic because it is moving
Explanation:
yeah
Answer:
281.25 J
Explanation:
We are told that the two objects with masses m and 3m.
Also that energy stored in the spring is 375 joules.
Now, initially the centre of mass of the system took place at rest, it means v1 = v and v2 = v/3
Thus, from principle of conservation of energy, we have;
½mv² + ½(3m)(v/3)² = 375J
(m + 3m/9)½v² = 375
(4/3)m × ½v² = 375
Multiply both sides by ¾ to get;
½mv² = 375 × ¾
½mv² = 281.25 J
Therefore, energy of lighter body is 281.25 J
Answer:
= 4.38 × 10³⁴kgm²/s
Explanation:
Given that,
mass of moon m = 9.5 × 10²²kg
Orbital radius r = 4.28 × 10⁵km
Orbital period T = 28.9days
T = 28.9 × 24 × 60 × 60
= 2,496,960s
Angular momentum of the moon about the planet
L = mvr
L = mr²w
