Answer:
2 times
Explanation:
1st time on Feb. 20, 1962 at age 41
2nd time on Oct. 29, 1998 at age 77
Answer:
(a) 0.17 m
(b) 5.003 m
(c) 6.38 ×
N
(d) 7.37 ×
N
Explanation:
(a) The minimum value of
will occur when q3 = 0 m or at origin and q1, q2 are at 0.17 m so the distance between q3 and q1, q2 is 0.17 m, therefore the <em>minimum value of x= 0.17 m</em>.
(b) The maximum value of x will occur when q3 = 5 m because it is said in the question that 5 is the maximum distance travelled by q3. To find the hypotenuse i.e. the distance between q3 and q1,q2, we use Pythagoras theorem.

<em>Hence, the maximum distance is 5.002 m</em>
(c) For minimum magnitude we use the minimum distance calculated in (a)
Minimum Distance = 0.17 m
For electrostatic force= 

×
(d) For maximum magnitude, we use the maximum distance calculated in (b)
Maximum Distance = 5.002 m
Using the formula for electrostatic force again:
F = 
F= 7.37×
N
B. The gravity acceleration is in the same direction as the force of gravity, and thus towards the centre of the earth
Answer:
Explanation:
a )
from lens makers formula

f is focal length , r₁ is radius of curvature of one face and r₂ is radius of curvature of second face
putting the values

1.462 = 2 - 1 / r₂
1 / r₂ = .538
r₂ = 1.86 cm .
= 18.6 mm .
b )
object distance u = 25 cm
focal length of convex lens f = 1.8 cm
image distance v = ?
lens formula



.5555 - .04
= .515
v = 1.94 cm
c )
magnification = v / u
= 1.94 / 25
= .0776
size of image = .0776 x size of object
= .0776 x 10 mm
= .776 mm
It will be a real image and it will be inverted.