Memo GR 11 Ctest
Memo GR 11 Ctest
Memo GR 11 Ctest
Question 1
Question 2
2.1 RESULTANT VECTOR – is the single vector that will have the same effect as two or more vectors
acting together (2)
2.2 0N. The three forces acting on the block are in equilibrium. (2)
2.3 Fg = mg
= 3.265 x 9.8
= 32N, downwards
60o
Fg=32N T2=39N
(32mm)
T1=36N
70o
Marking Grid
Criteria Marks
1. Correct calculation of Gravitational Force (Weight) 1
2. Correct measurement of weight according to the scale (32mm) 1
3. Correct measurement of two angles 1
4. Correct measuremennt of T1 according to scale (36mm) 1
5. Correct measurement of T2 according to scale (39mm) 1
6. T1=36N and T2=39N 1
[10]
3.1 NORMAL FORCE – is the force exerted by a surface on an object in contact with it (2)
3.2.1
N Fapp
Ff
Fg or W
3.2.3 fk = μkN
= μkmg cos β
38.25= μk (7.5) (9.8) cos 30
μk = 0.60 (3)
4.1 Newton’s Second Law of motion states that- when a net force, Fnet, is applied to an object of
mass, m, it accelerates in the direction of the net force. That acceleration, a, is directly
proportional to the net force and inversely proportional to the mass (2)
4.2
T1 T2
WA WB (4)
[15]
Question 5
5.1 Newton’s Law of Universal Gravitation states that each particle in the universe exerts a
gravitational pull on every other particle. The force is directly proportional to the product of
the masses and inversely proportional to the square of the distance between them. (2)
[10]
Question 6
6.2.1
(2)
(2)
[7]
Question 7
7.1 ELECTRONEGATIVITY – is the attracting power an element has for its own bonding electrons
OR is a measure of how strongly an atom attracts the shared pair of electrons in a chemical
bond. (2)
7.2 (a) Fluorine (F), 4.0
(b) Oxygen (O), 3.5
(c) Nitrogen (N), 3.0
(d) Chlorine (Cl), 3.0 (4)
7.4 CO2 – the molecule is non-polar because the two oxygen atoms are on either sides of the
carbon, thus making both ends partially negative.
CCl4 – the Cl atoms surround the central C atom and are placed at equal angles, making the
outer part of the molecule to be partially negative. (4)
[18]
Question 8
8.1 The boiling points increases as you move down from B to D. (1)
8.2 This due to the increase in the strength of the intermolecular forces as you go down.
(2)
8.3 The type of the intermolecular force in A (NH3) is Hydrogen bonding.Hydrogen Bonding
is much stronger than the other intermolecular forces. So more energy will be required
to overcome the hydrogen bonding hence higher boiling point than expected (3)
[6]