# GSC101 Assignment 1 Solution and Discussion

• ``````Assignment # 1
``````

Semester: FALL 2019
General Science (GSC101)
Total Marks: 20
Due Date:
1st December, 2019

Objective:
The assignment has been designed to enhance your knowledge and understanding of Physics & Chemistry and their applications in your daily life.
Instructions:
• To solve this assignment, you should have good command over first 15 lectures.
• Do not rely only on handouts but watch the course video lectures and read additional material available online
• The assignment will not be accepted after due date. Zero marks will be awarded to the assignment that does not open or the file is corrupt.
• The assignment file must be an MS word (.doc) file format; Assignment will not be accepted in any other format.
• Use Math Type or Equation Editor etc for mathematical symbols.
• Zero marks will be awarded to the assignment if copied (from other student or copied from handouts or internet).
• Don’t wait for the last date to submit your assignment.
For any query about the assignment, contact only [email protected]
Do not post queries related to assignment on MDB.

««««««««««««««««««««««««Good Luck»»»»»»»»»»»»»»»»»»»»»»
Question No. 1
a) If the average velocity of the object in the given interval of time is zero then what will be value of its displacement? Explain the reason.
b) Is it possible that an object have weight but no mass? Explain the reason.
Marks = 5+5=10
Question No. 2 The required speed of a commercial aeroplane is 120 knots before it can take off. If this plane take 30 s to cover the runway then calculate
a) Acceleration
b) Runway length
[Hint: knot is nautical mile per hour or equal to half a meter per seconds]
Marks =5+5= 10

• Question No. 1
a) If the average velocity of the object in the given interval of time is zero then what will be value of its displacement? Explain the reason.
b) Is it possible that an object have weight but no mass? Explain the reason.
Marks = 5+5=10

Q.1 Solution:
a) If the average velocity is continuously zero then this is easy to deal with. The object has not moved at all and so its displacement is zero. If it has moved and the average velocity is zero, then this means that at the end of the time interval, the object was back where it started this means the displacement is zero and so the average velocity is zero over the time period.
b) It is not possible. Mass is quantity of matter in the body which remains always same everywhere. Weight is force of gravity which always changes with gravity. At enter of earth gravity is zero so weight is zero but mass of an object will not zero.

Question No. 2 The required speed of a commercial aeroplane is 120 knots before it can take off. If this plane take 30 s to cover the runway then calculate
a) Acceleration
b) Runway length
[Hint: knot is nautical mile per hour or equal to half a meter per seconds]
Marks =5+5= 10

Q.2 Solution:
1 Knot=1/1.944 meter per seconds

1 Knot=0.514 meter per seconds

120 Knot=0.514 ×120 meter per seconds

120 Knot≈61 meter per seconds

``````Acceleration
``````

Given:
Vi =0 ms-1
Vf =61 ms-1
t=30s
a=?
Solution:
a=∆v/∆t
a=(vf-vi)/∆t
a=(61-0)/30
a=2 ms^(-2)

``````Runway length
``````

Given:
Vi=0 ms-1
Vf =61 ms-1
t=30s
a=2ms-2
S=?
Solution:
s=V_i t+1/2 at^2
s=0×30+1/2(2)〖(30)〗^2
s=0+900
s=900 m

• Question No. 1
a) If the average velocity of the object in the given interval of time is zero then what will be value of its displacement? Explain the reason.
b) Is it possible that an object have weight but no mass? Explain the reason.
Marks = 5+5=10

Q.1 Solution:
a) If the average velocity is continuously zero then this is easy to deal with. The object has not moved at all and so its displacement is zero. If it has moved and the average velocity is zero, then this means that at the end of the time interval, the object was back where it started this means the displacement is zero and so the average velocity is zero over the time period.
b) It is not possible. Mass is quantity of matter in the body which remains always same everywhere. Weight is force of gravity which always changes with gravity. At enter of earth gravity is zero so weight is zero but mass of an object will not zero.

Question No. 2 The required speed of a commercial aeroplane is 120 knots before it can take off. If this plane take 30 s to cover the runway then calculate
a) Acceleration
b) Runway length
[Hint: knot is nautical mile per hour or equal to half a meter per seconds]
Marks =5+5= 10

Q.2 Solution:
1 Knot=1/1.944 meter per seconds

1 Knot=0.514 meter per seconds

120 Knot=0.514 ×120 meter per seconds

120 Knot≈61 meter per seconds

``````Acceleration
``````

Given:
Vi =0 ms-1
Vf =61 ms-1
t=30s
a=?
Solution:
a=∆v/∆t
a=(vf-vi)/∆t
a=(61-0)/30
a=2 ms^(-2)

``````Runway length
``````

Given:
Vi=0 ms-1
Vf =61 ms-1
t=30s
a=2ms-2
S=?
Solution:
s=V_i t+1/2 at^2
s=0×30+1/2(2)〖(30)〗^2
s=0+900
s=900 m  | |