Jee Mains 2023 Laws Of motion Pyqs
Question 1.
A block of mass 5 kg is placed at rest on a table of rough surface. Now, if a force of 30N is applied in the direction parallel to surface of the table, the block slides through a distance of 50 m in an interval of time 10s. Coefficient of kinetic friction is (given, g = 10 m/s^2):
(1) 0.60
(2) 0.75
(3) 0.50
(4) 0.25
Answer . (3)
Question 2.
As shown in the figure a block of mass 10 kg lying on a horizontal surface is pulled by a force F acting at an angle 30°, with horizontal. For μs = 0.25, the block will just start to move for the value of F: [Given g = 10 m/s^2.]
(1) 33.3 N
(3) 20 N
(2) 25.2 N
(4) 35.7 N
Answer .(2)
Question 3.
Answer . (b)
Question 4.
Given below are two statements :
Statement-I : An elevator can go up or down with uniform speed when its weight is balanced with the tension of its cable.
Statement-II : Force exerted by the floor of an elevator on the foot of a person standing on it is more than his/her weight when the elevator goes down with increasing speed.
In the light of the above statements, choose the correct answer from the options given below :
(1) Both statement I and statement II are false.
(2) Statement I is true but Statement II is false .
(3) Both Statement I and Statement II are true .
(4) Statement I is false but Statement II is true.
Answer . (2)
Question 5.
As per given figure, a weightless pulley P is attached on a double inclined frictionless surface. The tension in the string (massless) will be (if g = 10 m/s^2.)
(1) (4√3+1)N
(3) 4(√3-1)N
(2) 4(√3 +1)N
(4) (4√3-1)N
Answer . (2)
Question 6.
Consider a block kept on an inclined plane (inclined at 45°) as shown in the figure. If the force the coefficient of friction between the block and inclined plane (μ) is equal to :
(1) 0.33
(2) 0.60
(3) 0.25
(4) 0.50
Question 7.
A block of mass m slides down the plane inclined at angle 30° with an acceleration g/4 The value of coefficient of kinetic friction will be :
(1) 2√3+1 / 2
(2) 1/2√3
(3) √3/2
(4) 2√3-1/2
Answer . (2)
Question 8.
The time taken by an object to slide down 45° rough inclined plane is n times as it takes to slide down a perfectly smooth 45° incline*plane. The coefficient of kinetic friction between the object and the incline plane is
Question 9.
A force acts for 20 s on a body of mass 20 kg, starting from rest, after which the force ceases and then body describes 50 m in the next 10 s. The value of force will be:
(1) 40 N
(3) 20 N
(2) 5 N
(4) 10 N
Answer . (2)
Question 10.
The figure represents the momentum time (p-t) curve for a particle moving along an axis under the influence of the force. Identify the regions on the graph where the magnitude of the force is maximum and minimum respectively?
If (t3-t2)< t1.
Answer . (2)
Question 11.
A block of √3 kg is attached to a string whose other end is attached to the wall. An unknown force F is applied so that the string makes an angle of 30° with the wall. The tension T is :
(Given g = 10 m/s^2)
(1) 20N
(2) 25N
(3) 10N
(4) 15N
Answer . (1)
(Given g = 10 m/s^2.)
(1) 800√2
(4) 200√3
Answer . (2)
A body of mass 10 kg is moving with an initial speed of 20 m/s. The body stops after 5 s due to friction between body and the floor. The value of the coefficient of friction is: (Take acceleration due to gravity g = 10 m/s^2.)
(1) 0,2
(3) 0.5
(2) 0.3
(4) 0.4
Answer . (d)
