2009 - JAMB Physics Past Questions and Answers - page 4

coefficient of friction = (F)/R = (F)/ mg = (500)/80 x 10
= 0.625

V.R = (1)/sinθ = (1)/sin 30 = (1)/(1)/2 = 2

pressure in fluid is given by P = hlg.
∴ fluid pressure depends on height of liquid column, h, density of liquid p and acceleration of free fall 8. it is therefore independent of type of container and constituents of the liquid

Work done on a stretched cord
= Average force x extension
= (10 + 0)/2 x 1.2 x 10^-2
= 6.0 x 10^-2J

Weight of glycerine displaced = weight of water dispalced
Mgh glycerine = Mgh water
Pvgh glycerine = Pvgh water
0.4V P glycerine = (0.5v)/v.4v P water = 1.25
(Polycerine)/p water =
But density of substance = relative density x density of water = 1. 25 x 1000kgm³ = 1250kgm^-3

A pyrometer is instrument for measuring high temperature.
The optical pyrometer is one in which the luminous radiation from the hot body is compared with that from a known source.

Anomalous expansion of water is at temperature ranges 0°c to 4°c u. water contract when heated from 0°c to 4°c. thus the volume of water is least at 4°c

Energy supplied bythe heater = heater gained by water
pt = MCAθ
1000 x 300 = m x 4200(100 - 30)
m = (1000 x 300)/4200 x 70 = 1.02 kg

Liquid boils when its sup. is equal to the atmospheric pressure.

Heat supplied = Heat gained
pt = ml
T = (ml)/p = (2 x 2.3 x 10⁶)/1000 = 4.6 x 10³ sec