JEE Main Previous Year Questions (2025): Newton's Laws of Motion

 Page 1


JEE Main Previous Year Questions 
(2025): Newton's Laws of Motion  
Q1: A balloon and its content having mass ?? is moving up with an acceleration ' ?? '. 
The mass that must be released from the content so that the balloon starts moving up 
with an acceleration ' 3 a' will be 
(Take ' ?? ' as acceleration due to gravity) 
JEE Main 2025 (Online) 28th January Evening Shift 
Options: 
A. 
3????
2?? +?? 
 
B. 
2????
3?? +?? 
 
C. 
3????
2?? -?? 
 
D. 
2????
3?? -?? 
 
Answer: B 
Solution: 
 
 
Page 2


JEE Main Previous Year Questions 
(2025): Newton's Laws of Motion  
Q1: A balloon and its content having mass ?? is moving up with an acceleration ' ?? '. 
The mass that must be released from the content so that the balloon starts moving up 
with an acceleration ' 3 a' will be 
(Take ' ?? ' as acceleration due to gravity) 
JEE Main 2025 (Online) 28th January Evening Shift 
Options: 
A. 
3????
2?? +?? 
 
B. 
2????
3?? +?? 
 
C. 
3????
2?? -?? 
 
D. 
2????
3?? -?? 
 
Answer: B 
Solution: 
 
 
 
 
 
?? - ???? = ????
?? = ???? + ????
?? - (?? - ?? )?? = (?? - ?? )3?? Put F
Ma + mg- mg+ xg = 3ma- 3xa
x =
2ma
 g+ 3a
 
 
Q2:  
 
A body of mass 1 kg is suspended with the help of two strings making angles as shown 
in figure. Magnitudes of tensions ?? ?? and ?? ?? , respectively, are (in ?? ) : 
(Take acceleration due to gravity ???? ?? /?? ?? ) 
Options: 
A. 5v3,5 
B. 5v3,5v3 
C. 5,5 
D. 5,5v3 
Answer: A 
Page 3


JEE Main Previous Year Questions 
(2025): Newton's Laws of Motion  
Q1: A balloon and its content having mass ?? is moving up with an acceleration ' ?? '. 
The mass that must be released from the content so that the balloon starts moving up 
with an acceleration ' 3 a' will be 
(Take ' ?? ' as acceleration due to gravity) 
JEE Main 2025 (Online) 28th January Evening Shift 
Options: 
A. 
3????
2?? +?? 
 
B. 
2????
3?? +?? 
 
C. 
3????
2?? -?? 
 
D. 
2????
3?? -?? 
 
Answer: B 
Solution: 
 
 
 
 
 
?? - ???? = ????
?? = ???? + ????
?? - (?? - ?? )?? = (?? - ?? )3?? Put F
Ma + mg- mg+ xg = 3ma- 3xa
x =
2ma
 g+ 3a
 
 
Q2:  
 
A body of mass 1 kg is suspended with the help of two strings making angles as shown 
in figure. Magnitudes of tensions ?? ?? and ?? ?? , respectively, are (in ?? ) : 
(Take acceleration due to gravity ???? ?? /?? ?? ) 
Options: 
A. 5v3,5 
B. 5v3,5v3 
C. 5,5 
D. 5,5v3 
Answer: A 
Solution: 
 
 
T
1
= mgcos?30
°
 
T
2
= mgsin?30
°
 
 
 
Q3: A body of mass ?? is suspended by two strings making angles ?? ?? and ?? ?? with the 
horizontal ceiling with tensions ?? ?? and ?? ?? simultaneously. ?? ?? and ?? ?? are related by 
?? ?? = v?? ?? ?? , the angles ?? ?? and ?? ?? are 
JEE Main 2025 (Online) 4th April Morning Shift 
Options: 
A. ?? 1
= 30
°
?? 2
= 60
°
 with ?? 2
=
3mg
4
 
B. ?? 1
= 45
°
?? 2
= 45
°
 with ?? 2
=
3????
4
 
C. ?? 1
= 30
°
?? 2
= 60
°
 with ?? 2
=
4????
5
 
D. ?? 1
= 60
°
?? 2
= 30
°
 with ?? 2
=
????
2
 
Answer: D 
Solution: 
Page 4


JEE Main Previous Year Questions 
(2025): Newton's Laws of Motion  
Q1: A balloon and its content having mass ?? is moving up with an acceleration ' ?? '. 
The mass that must be released from the content so that the balloon starts moving up 
with an acceleration ' 3 a' will be 
(Take ' ?? ' as acceleration due to gravity) 
JEE Main 2025 (Online) 28th January Evening Shift 
Options: 
A. 
3????
2?? +?? 
 
B. 
2????
3?? +?? 
 
C. 
3????
2?? -?? 
 
D. 
2????
3?? -?? 
 
Answer: B 
Solution: 
 
 
 
 
 
?? - ???? = ????
?? = ???? + ????
?? - (?? - ?? )?? = (?? - ?? )3?? Put F
Ma + mg- mg+ xg = 3ma- 3xa
x =
2ma
 g+ 3a
 
 
Q2:  
 
A body of mass 1 kg is suspended with the help of two strings making angles as shown 
in figure. Magnitudes of tensions ?? ?? and ?? ?? , respectively, are (in ?? ) : 
(Take acceleration due to gravity ???? ?? /?? ?? ) 
Options: 
A. 5v3,5 
B. 5v3,5v3 
C. 5,5 
D. 5,5v3 
Answer: A 
Solution: 
 
 
T
1
= mgcos?30
°
 
T
2
= mgsin?30
°
 
 
 
Q3: A body of mass ?? is suspended by two strings making angles ?? ?? and ?? ?? with the 
horizontal ceiling with tensions ?? ?? and ?? ?? simultaneously. ?? ?? and ?? ?? are related by 
?? ?? = v?? ?? ?? , the angles ?? ?? and ?? ?? are 
JEE Main 2025 (Online) 4th April Morning Shift 
Options: 
A. ?? 1
= 30
°
?? 2
= 60
°
 with ?? 2
=
3mg
4
 
B. ?? 1
= 45
°
?? 2
= 45
°
 with ?? 2
=
3????
4
 
C. ?? 1
= 30
°
?? 2
= 60
°
 with ?? 2
=
4????
5
 
D. ?? 1
= 60
°
?? 2
= 30
°
 with ?? 2
=
????
2
 
Answer: D 
Solution: 
 
 
T
1
sin??? 1
+ T
2
sin??? 2
= mg& T
1
= v3 T
2
 
? T
2
[v3sin??? 1
+ sin??? 2
] = mg 
for ?? 1
= 60
°
&?? 2
= 30
°
 
T
2
=
mg
2
 
 
Q4: An object with mass ???????? moves along ?? -axis with speed ?? = ?? v?? ?? /?? . The force 
acting on the object is : 
JEE Main 2025 (Online) 7th April Evening Shift 
Options: 
A. 8 N 
B. 4 N 
C. 5 N 
D. 6 N 
Answer: B 
Solution: 
To find the force acting on the object, we use the formula ?? = ?? × ?? , where ?? is the force, ?? is 
the mass, and ?? is the acceleration. 
The velocity ?? is given as ?? = 4v?? . 
Squaring both sides, we have ?? 2
= 16?? . 
Differentiate ?? 2
 with respect to ?? : 
2?? ????
????
= 16 
Solving for 
????
????
, we find: 
?????? ????
=
16
2
= 8 
The force ?? is then calculated as: 
?? = 0.5 × 8 = 4 N 
Thus, the force acting on the object is 4 N . 
Page 5


JEE Main Previous Year Questions 
(2025): Newton's Laws of Motion  
Q1: A balloon and its content having mass ?? is moving up with an acceleration ' ?? '. 
The mass that must be released from the content so that the balloon starts moving up 
with an acceleration ' 3 a' will be 
(Take ' ?? ' as acceleration due to gravity) 
JEE Main 2025 (Online) 28th January Evening Shift 
Options: 
A. 
3????
2?? +?? 
 
B. 
2????
3?? +?? 
 
C. 
3????
2?? -?? 
 
D. 
2????
3?? -?? 
 
Answer: B 
Solution: 
 
 
 
 
 
?? - ???? = ????
?? = ???? + ????
?? - (?? - ?? )?? = (?? - ?? )3?? Put F
Ma + mg- mg+ xg = 3ma- 3xa
x =
2ma
 g+ 3a
 
 
Q2:  
 
A body of mass 1 kg is suspended with the help of two strings making angles as shown 
in figure. Magnitudes of tensions ?? ?? and ?? ?? , respectively, are (in ?? ) : 
(Take acceleration due to gravity ???? ?? /?? ?? ) 
Options: 
A. 5v3,5 
B. 5v3,5v3 
C. 5,5 
D. 5,5v3 
Answer: A 
Solution: 
 
 
T
1
= mgcos?30
°
 
T
2
= mgsin?30
°
 
 
 
Q3: A body of mass ?? is suspended by two strings making angles ?? ?? and ?? ?? with the 
horizontal ceiling with tensions ?? ?? and ?? ?? simultaneously. ?? ?? and ?? ?? are related by 
?? ?? = v?? ?? ?? , the angles ?? ?? and ?? ?? are 
JEE Main 2025 (Online) 4th April Morning Shift 
Options: 
A. ?? 1
= 30
°
?? 2
= 60
°
 with ?? 2
=
3mg
4
 
B. ?? 1
= 45
°
?? 2
= 45
°
 with ?? 2
=
3????
4
 
C. ?? 1
= 30
°
?? 2
= 60
°
 with ?? 2
=
4????
5
 
D. ?? 1
= 60
°
?? 2
= 30
°
 with ?? 2
=
????
2
 
Answer: D 
Solution: 
 
 
T
1
sin??? 1
+ T
2
sin??? 2
= mg& T
1
= v3 T
2
 
? T
2
[v3sin??? 1
+ sin??? 2
] = mg 
for ?? 1
= 60
°
&?? 2
= 30
°
 
T
2
=
mg
2
 
 
Q4: An object with mass ???????? moves along ?? -axis with speed ?? = ?? v?? ?? /?? . The force 
acting on the object is : 
JEE Main 2025 (Online) 7th April Evening Shift 
Options: 
A. 8 N 
B. 4 N 
C. 5 N 
D. 6 N 
Answer: B 
Solution: 
To find the force acting on the object, we use the formula ?? = ?? × ?? , where ?? is the force, ?? is 
the mass, and ?? is the acceleration. 
The velocity ?? is given as ?? = 4v?? . 
Squaring both sides, we have ?? 2
= 16?? . 
Differentiate ?? 2
 with respect to ?? : 
2?? ????
????
= 16 
Solving for 
????
????
, we find: 
?????? ????
=
16
2
= 8 
The force ?? is then calculated as: 
?? = 0.5 × 8 = 4 N 
Thus, the force acting on the object is 4 N . 
Q5: A body of mass 2 kg moving with velocity of ??? ? 
????
= ?? ??ˆ + ?? ??ˆ ????
-?? enters into a 
constant force field of 6 N directed along positive z -axis. If the body remains in the 
field for a period of 
?? ?? seconds, then velocity of the body when it emerges from force 
field is. 
JEE Main 2025 (Online) 8th April Evening Shift 
Options: 
A. 3??ˆ + 4??ˆ + v5?? ˆ
 
B. 4??ˆ + 3??ˆ + 5?? ˆ
 
C. 3??ˆ + 4??ˆ - 5?? ˆ
 
D. 3??ˆ + 4??ˆ + 5?? ˆ
 
 
Answer: D 
Solution: 
To determine the velocity of the body as it emerges from the force field, we can break this 
process down as follows: 
Force and Acceleration Calculation: 
The body is subjected to a constant force of 6 N , which acts along the positive z -axis. The mass 
of the body is 2 kg . 
Using Newton's second law, ?? 
= ?? ?? , the acceleration ??  can be calculated as: 
?? =
?? 
?? =
6?? ˆ
2
= 3?? ˆ
 ms
-2
 
Initial Velocity: 
The initial velocity of the body is given by: 
??? = 3??ˆ + 4??ˆ ms
-1
 
Time of Motion: 
The time the body spends in the force field is: 
?? =
5
3
 seconds 
 
Final Velocity Calculation: 
The final velocity ??  is given by the equation of motion: 
?? = ??? + ?? ?? 
Substituting the known values: