# WAEC GCE Physics Essay Live Answers

on September 16, 2015

(5a) Tensile stress is the ratio of load or force(F) to its cross-sectional area
(A). It is measured in Nm^-2 or N/m^2.

(5b) Young modulus is the ratio of tensile or compressive stress to
compressive strain. It is demoted by E and measured in N/m^2 or Nm^-2(S.I unit).
[9/15, 10:31 AM] Abdlhman Adera: (1a)
Acceleration(a)=change in velocity/time
Velocity=displacement/time
V=L/T
V=LT^-1
a=LT^-2 (1b)
Presssure=force/Area
P=F/A
F=ma=MLT^-2
P=MLT^-2/L^2
=ML*L^-2T^-2 P=ML^-1T^-2

(1c)
Density=M/L^3
=ML^-3

(2)
Initial velocity(u)=42ms^-1
Angle(tita)=30degrees
H=u^2sin^2(tita)/2g
H=42^2*sin^2(30degrees)/2*10
H=42*42*(0.5)^2/20 H=22.05m

(3) Mercury does not wet glass because of its high cohesion and low adhesion to the glass unlike water which has adhesion force with glass is greater
than the force of cohesion with water molecules.

(4)
=(12-8)/(10-5)
18/(F-10)=4/5
4F-40=90
4F=130 F=130/4
=32.5N
[9/15, 10:56 AM] Abdlhman Adera: (8a)
(i)Relative motion is the motion of a body say A in reference to another body say B
(ii)Velocity of the car
=80km/hr-60km/hr
=20km/hr

(8b)
(i)force is the push or pull on a body and anything that makes a body to move
(ii)Contact force;push,tension,reaction Field forces;gravitational force,electrostatic force,magnetic force. 