Na two identical balls are dropped from a tall

[N/A]
Two identical balls are dropped from a tall building, one a few seconds after the other. Air resistance is not negligible. As the balls fall, the distance
between the balls will
A. decrease.
B. increase.
C. increase then remain constant.
D. remain constant.

Examiners report
C
[N/A]
Which of the following quantities can be determined from a speed-time graph of a particle travelling in a straight line?
Markscheme
Examiners report
D
[N/A]
A truck is pulled up an inclined plane at constant speed by an electric motor. The gain in potential energy of the truck is 48 kJ. The efficiency of the
electric motor is
How much energy is dissipated in pulling the truck up the plane?
.
Markscheme
Examiners report
B
Candidates should understand technical language such as ‘dissipated’ even if they are working in a second language.

Markscheme
A football is kicked with an initial velocity at an angle to the horizontal and reaches the ground seconds later.
Ignoring air resistance what is the range of the football?
Examiners report
Markscheme
Examiners report
[N/A]
Which of the following is always true for an object moving in a straight line at constant speed?
A. No forces act on the object.
B. No resultant force acts on the object.
C. The momentum of the object is zero.
D. No work is being done on the object.
B
No work is done only if there are no forces on the object. So clearly the only possible answer is B.
A student throws a stone with velocity at an angle to the vertical from the surface of a lake. Air resistance can be ignored. The acceleration due to
gravity is .

Markscheme
Examiners report
A.
B.
C.
D.
D
Clearly when , so A and C must be incorrect. The relevant equation of motion relating s , v , a , t includes , so D must be the correct
response.
What is the time taken for the stone to hit the surface of the lake?
Markscheme
Examiners report
C
[N/A]
If a moving object is subject to a constant force, which of the following can be correctly deduced from Newton’s first law?
Two isolated spherical planets have the same gravitational potential at their surfaces. Which ratio must also be the same for the two planets?