Answer:
(a) convex mirror
(b) virtual and magnified
(c) 23.3 cm
Explanation:
The having mirror is convex mirror.
distance of object, u = - 20 cm
magnification, m = 1.4
(a) As the image is magnified and virtual , so the mirror is convex in nature.
(b) The image is virtual and magnified.
(c) Let the distance of image is v.
Use the formula of magnification.

Use the mirror equation, let the focal length is f.

Radius of curvature, R = 2 f = 2 x 11.67 = 23.3 cm
Answer:
1.58 W
Explanation:
Since the sound spreads uniformly in all directions, it must be in a form of a circle with radius of 12 m. So the area of the circle is

From the intensity of the sound we can calculate the power at 12 m

Answer:
The time is 
The speed is 
Explanation:
From the question we are told that
The height of the cliff is 
Generally from kinematic equation we have that

before the jump the persons initial velocity is u = 0 m/s
So

=> 
Generally from kinematic equation

=> 
=> 
Hinge joints would be your elbow, your knee and, believe it or not, your ankle as well!