Fill in the balnks with a suitable word or words. (4 marks)
(a)When an object is at the centre of curvatureof a concave mirror the magnification is
________ .
(b)The distance between the pole and the focus of a concave or convex mirror is called
the ________ of a concave or convex mirror.
(c) The velocity of light in air is _____ ms-1.
(d) The electrons closer to the nucleus are called _____ electrons.
- (a) State the laws of reflection of light. Find the wavelength of a wave with frequency 1000 Hz and velocity
344 ms-1. (3 marks )
(b) A concave mirror can produce an image which is twice the size of the object. Draw a ray diagram to show
this. (3 marks ) - (a) Define specific heat capacity. A calorimeter at 15 ℃ contains 0. 1 kg of carbon. The calorimeter is made
of aluminum and its mass is 0.02 kg. When 892 J of heat is added to the calorimeter and carbon, the
temperature increases to 28 ℃ . Find the specific heat capacity of carbon. Assume that the specific heat
capacity for aluminum at said temperature range is 900 J kg-1 K-1. (3 marks )
(b) A radar antenna of a wave with frequency 1000 Hz and wavelength 0.5 m. (3 marks ) - (a)The glancing angle of a ray incident on a plane mirror is 60° . Find the angle between the incident ray and
the new reflected ray when the plane mirror is rotated(a) through 15° in the clockwise direction,(b)through
30° in the anticlockwise direction. (3 marks )
(b) A 60 kg woman is on a diet that provides her with 1.046 J daily . If this amount of heat is added to 60 kg
of water at 37° C what will be the final temperature of the water? (3 marks )
SECTION (B)
(Answer ALL questions) - (a) 0.5 kg of orange squash at 30℃ is placed in a refrigerator which can remove heat at an average rate of
25Js-1. How long will it take to cool the orange squash to 5℃?The specific heat capacity of orange squash
is 4200 J kg-1℃-1. (4 marks )
(b) An object is 200cm in fro (4 marks )
7.(a)A heat resistant glass at 15℃ is fully filled with 250cm3 of glycerine.If the temperature increases to 25℃
how much glycerine overflows? The coefficient of volume expansion of glycerine is 5.1x 10-4K-1 and that
of heat resistant glass is 0.09x10-4K-1 . (4 marks )
(b)An object 5cm tall is 15 cm in front of a concave mirror of focal length 10cm.Can its image be receive on
a screen each side 9cm long? If so, in which position should the screen be placed? (4 marks )
8.(a) If the temperature of the medium is increased from 0℃ to 40℃, by what percentage has the velocity of
sound increased? (4 marks )
(b) A stone is dropped in a well whose water level is 20m down. How much time elapses until the sound of
the splash is heard? Assume the speed of sound to be 340ms-1. (4 marks )