260 joules is hopefully right.
Answer:
1. Lateral inversion is a phenomenon in which left appears to be right and vice versa. It is due to direction that light follows when it strikes a reflecting surface, generally a mirror.
These are the letters which don't show lateral inversion A,H,O,T,U
2. USES OF CONCAVE MIRROR
They are used as shaving mirrors to see a larger image of the face.
Dentists use concave mirrors to view large images of the teeth of the patients.
USES OF CONVEX MIRROR
It is is used as a rear view mirror in vehicles.
It is used as a vigilance mirror.
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Answer:
21 m
Explanation:
The motion of the frog is a uniform motion (constant speed), therefore we can find the distance travelled by using

where
d is the distance covered
v is the speed
t is the time
The frog in this problem has a speed of
v = 2.1 m/s
and therefore, after t = 10 s, the distance it covered is

Answer:
speed of each marble after collision will be 1.728 m/sec
Explanation:
We have given mass of the marble 
Velocity of marble 
Its collides with other marble of mass 25 gram
So mass of other marble 
Second marble is at so 
We have to find the velocity of second marble
From momentum conservation we know that
, here v is common velocity of both marble after collision
So 
v = 1.428 m /sec
So speed of each marble after collision will be 1.728 m/sec