Answers for Week 9

Dear all,

Here are the answers for the last post.

1. Tom observed Tim ___________ out a wallet from his bag.

(a) took
(b) takes
(c) take

Verb (subject) Verb --> 2nd verb is always present tense, plural form.

2. The pack of cards _______ stolen yesterday.

(a) is
(b) was
(c) are

Pack of cards. I am looking at the word pack (singular) and yesterday (past tense).

3. Either Peter or the boys ______________ going to the fun fair today.

(a) are
(b) is
(c) were

4. Neither the bandits nor the policeman _____________ to leave the crime scene.

(a) are
(b) is

Neither....nor (Look at the 2nd subject) Policeman (singular)

5. While running halfway, the athlete ____________ injured by the side of the track.

(a) pulled over
(b) pulled up
(c) pulled in
(d) pulled under

Phrasal verb. keywords are 'athlete' and 'injured by the side'

6. He was taken ___________ by the sudden appearance of the man from the dark corner.

(a) over
(b) aback
(c) against
(d) from

Phrasal verb. taken aback --> shocked.

Science

Q1. A ball was placed on a 1metre high chair. Tom then push the ball forward and it landed onto the ground. 

a) Explain how the force exerted by Tom help push the ball forward and onto the floor.

Forces can cause a stationary object to move. When Tom pushes the ball forward, gravitational potential energy is converted to kinetic energy and the force pushes the ball forward and onto the floor.

b) It this force a pull or push?

Push

c) Complete the energy conversion.

Gravitational potential energy --> Kinetic energy --> Sound energy + Heat energy

d) As the ball gets lower, the amount of gravitational potential energy decreases while the amount of kinetic energy increases.

Q2. Ahmad put a glass cup of warm water in the open. He noticed X forming on the outer surface of the glass after some time.

a) What is X?

Water droplets

b) How is X formed?

'WCCW' acronym!

When the warm water vapour from the surrounding air touches the cool surface of the glass, it condenses into water droplets. 

c) If Ahmad wants to reduce the amount of X on the outer surface of the glass, what can he do?

1. He can put an object with a cooler surface at the top of the glass surrounding it.
2. He can increase the temperature of the glass so that it becomes warmer and less water vapour will condense on its warmer surface.

Thank you,
Sincerely,
Mr Nelson Ong