Answer:
C) 10 cm
Explanation:
We shall first calculate the focal length of the mirror.
object distance u = 20 cm ( negative )
Image distance v = 12 cm ( negative )
using mirror formula
1/ v + 1 /u = 1/ f
-1/12 - 1/ 20 =1/ f
f =- 7.5 cm
In the second case
u = - 30 cm
f = - 7.5 cm
i / v + 1 / u = 1 / f
1 / v - 1/30 = - 1/ 7.5
v = -10 cm
Answer is C that is 10 cm
Answer:
516526.863 m
Explanation:
From the question given above, the following data were obtained:
Acceleration due to gravity (g) = 2.24 m/s²
Mass (M) = 8.96×10²¹ Kg
Gravitational constant (G) = 6.67×10¯¹¹Nm²/Kg²
Radius (r) =?
The radius of the planet can be obtained as follow:
g = GM/r²
2.24 = 6.67×10¯¹¹ × 8.96×10²¹ / r²
2.24 = 5.97632×10¹¹ / r²
Cross multiply
2.24 × r² = 5.97632×10¹¹
Divide both side by 2.24
r² = 5.97632×10¹¹ / 2.24
r² = 2.668×10¹¹
Take the square root of both side
r = √2.668×10¹¹
r = 516526.863 m
Thus, the radius of the planet is 516526.863 m
Answer:
, downward
Explanation:
There is only one force acting on the ball during its motion: the force of gravity, which is given by
where
m is the mass of the ball
is the acceleration of gravity (downward)
According to Newton's second law,
where F is the net force on the object and a is its acceleration. Rearranging for a,
As we said, the only force acting on the ball is gravity, so F = mg and the acceleration of the ball is:
Therefore, the ball has a constant acceleration of downward for the entire motion.
Answer:
A) x4
Explanation:
Magnification is equal to image size divided by the actual size, or M = I/A.
The image size is the student's drawing, which is 28.8 cm, and the actual size is 7.2 cm. Divide them, and cancel out the units, and you should get:
28.8 cm/7.2 cm = 4
