*2017 PRIVATE WASSCE PHYSICS ESSAY*


*1-10- ACBAABCABC*

*11-20- CADDCBABBA*

*21-30- CABADBCCCA*

*31-40- BAABCACACB*

*41-50- ABBACBADAB*

*READ BEFORE YOU SHADE*

*VERIFIED AND confirmed*

*Question one*
(a)  Horizontal speed just before it strikes floor = ucos(theta)
                                                                                    = 10cos0°
                                                                                    = 10 m/s

(b) t = √(2g/h)
        = √(2*10*1)
        = √20
        = 4.47s


Question 4
(a)  given: u = 20m/s
                   t = 4s
                   g = 10m/s²
                   h = ?
    Using s = ut - ½gt²
               s = 20(4) - ½(10)(4)²
               s = 0m

(b)   The inference is that after 4s, the ball returns back to the plane of projection

Question 3
Magnetic materials: ¶ Iron ¶ Cobalt ¶ Nickel

Question 2
¶ medical uses
¶ welding and cutting
¶ military uses for defense and counter measures

Question 5
The factors that determine the location of a solar power station are
¶ Intensity of sun light
¶ surface slope
¶ feeder capacity of the distribution center

Physics
8ai)

Force is a push or pull which changes a body's state of rest or uniform motion in a straight line.

II)a) field force
  b) contact force
=================
8bi)
Bodies streamlined in
Shape move through fluid so as to oppose or overcome the motion  of the fluid

II) a) fish
    B) submarine
==================
8c)

Mass= 1.3 kg
F= 1.2 m
V= 7.0 m/s

Drawing

II) Acceleration
Note , V²= U² + 2as

Where S=r=1.2 m

(7.0)²= 0²+2× a (1.2)

= 49/2.4 = 2.4a/2.4

a = 20.4

B) Force=?
From force = MA
Force =1.3×20.4
Force =25.52
=========={={{{{{{============

*Question 9*
(a) Poor conductors of heat application: ¶ Coat (Trapped air in between the fabric)
                                                                        ¶ The hair and the fur of animals are bad conductors of
                                                                            heat and they protect them from cold .

(b) Renewable: Water, corn stalk
     Non-renewable: coal, natural gasgas

(c) A closed is a physical system so far removed from other systems that it does not interact with them.

d)  heat required to melt = mc∆ + ml
    *NB*: Not sure of the temperature given, if it is -3°C or -5°C, However, *Using -3°C*
Heat = (0.1×2200×3)+(0.1×2.26×10^6)
           = 226660 J

e) (i) Given:  75 heart beats in 1 min
                      Therefore in 1 hour, we have (75×60) heart beats = 4500 heart beats
         Also given:  2J of energy is expended in 1 heart beat
                       Therefore for 4500 heart beats, energy expended = (4500×2) J = 9000J

e) (ii)  Energy = mc∆
           9000 = (0.25×4200×∆)
           9000 = 1050∆
           ∆ = 9000/1050
           Temperature rise = 8.57°C
========={={{===================
*Question 11*

(a)  ¶ Electrical method
       ¶ Contact method

(b)  Electric lines of force are imaginary lines drawn in an electric field in such a way that the direction at any point gives the direction of the electric field at such a point

(c)  QR = SP

(d)  Resistivity is the resistance of a unit length of material of unit cross-sectional area

d)  heat required to melt = mc∆ + ml
    *NB*: Not sure of the temperature given, if it is -3°C or -5°C, However, *Using -3°C*
Heat = (0.1×2200×3)+(0.1×2.26×10^6)
           = 226660 J

(e)  Given: F = 50Hz
                   L = 10 mH (10×10^-³H)
       Inductive reactance, XL = 2πFL
                                                  = 2×3.14×50×10×10^-³
                                                  = 3..14 ohms

(f)  If voltmeter reads 12V, over the 500 ohms, then using I = V/R
                                                            current in the circuit is I = 12/500
                                                                                                     I = 0.024A
     Hence over the 200 ohms, V = IR
                                                    V = 0.024×200
                                                    V = 4.8 VOLTS
     Voltmeter will read 4.8 volts

Post a Comment

 
Top