Friction is caused by the ......... on the two surfaces in contact.
irregularities
smoothness
densities
gaps
A.
irregularities
An image formed by a concave mirror on a screen is called........
Virtual image
Real image
Inverted image
Erect image
If the force applied on the object is in the direction of its motion, the speed of the object.......
increases
stops
decreases
no effect
The impression of an image persists on the retina for about _________ of a second.
1/10 th
1/8 th
1/16 th
1/5 th
Convex and concave mirrors are examples of
plane mirrors
spherical mirrors
inverted mirror
erect mirror
The reflection formed by the plane mirror is ...........
vertical inversion
a real image
lateral inversion
an enlarged image
The distance-time graph for the motion of an object moving with a constant speed is a .............
Dot
Circle
Straight Line
Curve
If an object moves in a circular path with uniform..........its motion is called uniform circular motion.
speed
time
velocity
acceleration
Who discovered electricity and invented the lightning rod and bifocals?
Kirkpatrick Macmillan
Benjamin Franklin
William Henry Fox Talbot
Sir Alexander Fleming