26. You see your face clearly if you look in a pool of still water. Which one of the following statements gives the best explanation for this observation?
B. Regular reflection of light happens on the surface of still water
27. What type of mirror do dentists usually use to see clearly the images of our teeth?
C. Concave Mirror
28. Where should the object be placed in front of a concave mirror to form a virtual and
C. Between the focus and the vertex
29. Which of the following equipment could magnify far objects and appear clearer?
C. Binoculars and telescope
30. What optical instrument uses both lens and mirror?
31. If a man wishes to use a plane mirror on a wall to view both his hands and his feet as he stands in front of the mirror the required length of the mirror is
b. equal to one half the height of the man.
32. When the image of an object is seen in a convex mirror, the image will
b. Always be virtual
33. When the image of an object is seen in a concave mirror, the image will
c. Maybe either real or virtual
34. Why are convex mirrors used on cars?
a. Convex mirrors have a wider field of view
35. You see the reflection of the clock without numbers in your plane mirror. The image
formed by the hands of the clock shows the time of 3:30. What is the real time?
36. Where should an object be placed in front of a concave mirror so that the image would
have the same size as an object?
b. At the center of the curvature
37. What type of lens produces smaller and upright images?
a. Concave lens
38. are images that are formed by the intersection of real refracted rays.
a. real images
39. is an object that attracts certain materials such as iron.
40. Listed below are non-magnetic except
41. If two magnets were in this order: NS NS they would?
42. What will happen if you strike an iron nail with a magnet?
b. The nail will become magnetic
43. Which of the following are ferromagnetic materials?
d. All of these
44. Early compasses were created with which of the following.
45. According to a Greek legend, who was the shepherd that first discovered the magnet?
46. Who conceptualized the theory which states that inside a magnet there are small regions
in which the magnetic direction of all atoms are a gned in the same directions?
b Domain Theory
47 The force that a magnet exerts on a certain material is called
c. magnetic force
48. What happens when two magnets with the same poles were brought closer to each
a. The two magnets repel each other
49. The strongest part of a magnet is/are
c the poles
50. What is the space or area around a magnet where the force is?
c. magnetic field
b. Magnetic field
Two balls of masses 200 kg moving in the same direction with velocities 2 m/s and 1 m/s respectively collide with each other. If the velocity of ball mass 200 get after collision becomes 1.165 m/s . Find the velocity of other ball.
Before Collision After Collision
Mass Velocity Mass Velocity
Ball 1 200 kg 2 m/s 200 Kg 1.165 m/s
Ball 2 200 Kg 1 m/s 200 Kg ?
Momentum before collision = Momentum after Collision
(200Kg ×2m/s) + (200Kg×1m/s) = (200 Kg ×1.165 m/s) + 200 Kg (V)
400 kg.m/s + 200 kg.m/s = 233 kg.m/s + 200 Kg (V)
600 kg.m/s = 233 kg.m/s + 200 Kg (V)
600kg.m/s -233 kg.m/s/200 Kg = V
367 kg.m/s / 200 kg = V
1.835 m/s = V
velocity of other ball is 1.835 m/s
It moves parallel direction. Backwards and forwards
yes because my science teacher proved it
No. It moves in perpendicular direction.
* The source is the straight line and the ribbon is the horizontal line.
law of acceleration: there are two objects, a car and a table. if you push each object with the same amount of force, the acceleration of the table is greater because it has less mass, while the car has lesser acceleration because it has greater mass.
law of interaction: you are rowing a small boat on a still river. you push the oars backwards so the same amount for force will push you forwards.