PHYSICS TESTLET II

ST. MARTIN’S GIRL’S SCHOOL KIBAGARE
P.O.BOX 14960-00800
FORM IV PHYSICS ASSIGNEMENT 11TH THURSDAY SEPTEMBER 2009
NAME: ______________________________________________________________
1. What is impulse?

a) Why are eggs packed in a soft tray?

b) A train accelerates uniformly from rest for 30seconds with an acceleration of 2ms-2. It then travels at a constant speed of21ms-1 for 2 minutes before slowing down with uniform deceleration to rest in further 15 seconds. Sketch a velocity time graph of the motion
Find:
i) The maximum speed.



ii) The acceleration while slowing down.

2. Show that pressure P in fluids is given by P=ρgh where ρ = density of the fluid, g=gravitational acceleration, h= height of fluid column
a) State Pascals principle of transmission of pressure in fluids.


b) State two applications of Pascal’s principle.

c) In a laboratory experiment, Agnes blew into one end of a U-tube containing water until the levels differed by 30cm. If the atmospheric pressure was 1.01 x 105Nm-2, calculate her lung pressure.


3. Define specific heat capacity of a substance.

a) A piece of iron of mass 200g and specific heat capacity 460JKg-1K-1 cools from 86oC to 28oC. Find the quantity of heat given out.


b) Figure 1 below shows a domestic electric refrigerator.

X=
Y=

i) Label the parts

ii) Explain the use of part X


iii) Explain the use of part Y