## Physics | Study Mode

Question 1
A
20ms2, 20ms1
B
25ms2, 250ms
C
20ms2 200ms4
D
10ms2 300ms-4
Explanation.
Ft = mv - mu
Ft = m (v-u)
100 x 10 = 5(v-0)
1000 = 5v
V = 200m/s
V = u at
200 = 0 mass
a = 20m/s2 (C)

Question 2
A
momentum is proportional to force action
B
action is equal to reaction but in the opposite direction
C
impulse force is inversely proportional to time
D
force is proportional to rate of change of momentum
Explanation.
The second law of motion states that a body which is subjected to a net
external force (F) acquires
acceleration which is directly proportional to the force and inversely proportional to the mass of the body i.e. F = ma
(C)

Question 3
A
heat energy
B
intent heat of fusion
C
specific latent heat of fusion
D
specific heat capacity
Explanation.
Specific latent heat of fusion (C)

Question 4
A
2.0 x 10-6m3
B
2.5 x 10-6m3
C
3.0 x10-6m3
D
2.0 x 10-6m3
Explanation.
Weight of liquid displaced = Upthrust
= (0.040 - 0.024)N
= 0.016N = 0.016/10 = 1.6 X 10-3kg
Volume of the object = Volume of liquid displaced
=

 Mass of liquid = 1.6 x 10-1kg density of liquid 800kgm-2

= 2.0 x 106m3 (A)

Question 5
A
change in momentum of a body
B
its unit is Ns
C
product of force and time
D
change in acceleration of a body
Explanation.
Impulse, Ft = m(v-u)

(D)

Question 6
A
57,708J
B
42,708J
C
35,208J
D
50,208J
Explanation.
Since I calorie = 4.184J
12,000 calorie = (4.184 x 12,000)J = 50.208J
heat supplied = Work done
() + U (internal energy)
50,208 = 7500J + 5
5 = (50.208 7500)J
= 42708J (A)

Question 7
A
convection
B
conduction
C
D
Explanation.
Convection is the transfer of heat from a hotter region of a Fluid to a colder region through the actual motion of the fluid (A)

Question 8
A
8.06KJ
B
706KJ
C
538KJ
D
6.72KJ
Explanation.
Heat required to change the phase of
mass, in of the substance is Q = rnLf
= 20kg x 336Kg-1
= 6.72 x 103J
= 6.72kJ (D)

Question 9
A
Alpha
B
x-rays
C
beta
D
neutron
Explanation.
Apha decay produces Helium particle
2He (A)

Question 10
A
2000 watt
B
3000 watt
C
4000 watt
D
5000 watt
Explanation.
Power, P = = FV

V = velocity
Power P = FV = (200N (20m/s)
= 4000W (C)

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