Slide 1 : P. K. BHARTI, I.I.T. KHARAGPUR Newton’s Laws
of Motion
Problems
24.06.2010 © 2007-10 P K Bharti, IIT Kharagpur
Slide 2 : P. K. BHARTI, I.I.T. KHARAGPUR NCERT
Problems
Slide 3 : P. K. BHARTI, I.I.T. KHARAGPUR Q1. Figure shows the position-time graph of a particle of mass 4 kg. What is the force on the particle for t < 0, t > 4 s, 0 < t < 4 s?
Slide 4 : P. K. BHARTI, I.I.T. KHARAGPUR Q2. A body of mass 0.40 kg moving initially with a constant speed of 10 m s-1 to the north is subject to a constant force of 8.0 N directed towards the south for 30 s. Take the instant the force is applied to be t = 0, the position of the body at that time to be x = 0, and predict its position at t = –5 s, 25 s, 100 s.
Slide 5 : P. K. BHARTI, I.I.T. KHARAGPUR Q3. A constant retarding force of 50 N is applied to a body of mass 20 kg moving initially with a speed of 15 m s-1. How long does the body take to stop ?
Slide 6 : P. K. BHARTI, I.I.T. KHARAGPUR Q4. Two bodies of masses 10 kg and 20 kg respectively kept on a smooth, horizontal surface are tied to the ends of a light string. A horizontal force F = 600 N is applied to (i) A, (ii) B along the direction of string. What is the tension in the string in each case? 10kg 20kg
Slide 7 : P. K. BHARTI, I.I.T. KHARAGPUR Q5. Two masses 8 kg and 12 kg are connected at the two ends of a light inextensible string that goes over a frictionless pulley. Find the acceleration of the masses, and the tension in the string when the masses are released. 8 kg 12 kg
Slide 8 : P. K. BHARTI, I.I.T. KHARAGPUR Q6. A man of mass 70 kg stands on a weighing scale in a lift which is moving (a) upwards with a uniform speed of 10 m s-1,
(b) downwards with a uniform acceleration of 5 m s-2,
(c) upwards with a uniform acceleration of 5 m s-2.
What would be the readings on the scale in each case?
(d) What would be the reading if the lift mechanism failed and it hurtled down freely under gravity ?
Slide 9 : P. K. BHARTI, I.I.T. KHARAGPUR Q7. A monkey of mass 40 kg climbs on a rope (Fig. 5.20) which
can stand a maximum tension of 600 N. In which of the
following cases will the rope break: the monkey
(a) climbs up with an acceleration of 6 m s-2
(b) climbs down with an acceleration of 4 m s-2
(c) climbs up with a uniform speed of 5 m s-1
(d) falls down the rope nearly freely under gravity?
(Ignore the mass of the rope).
Slide 10 : P. K. BHARTI, I.I.T. KHARAGPUR Q8. A monkey of mass 40 kg climbs on a rope which can stand a maximum tension of 600 N. In which of the following cases will the rope break: the monkey
(a) climbs up with an acceleration of 6 m s-2
(b) climbs down with an acceleration of 4 m s-2
(c) climbs up with a uniform speed of 5 m s-1
(d) falls down the rope nearly freely under gravity?
(Ignore the mass of the rope).
Slide 11 : P. K. BHARTI, I.I.T. KHARAGPUR H C Verma
Problems
Slide 12 : P. K. BHARTI, I.I.T. KHARAGPUR Q9. Two blocks A and B of mass mA and mB respectively are kept in contact on a frictionless table. The experimenter pushes the A from behind so that the blocks accelerate. If the block A exerts a force F on the block B, what is the force exerted by the experimenter on A? mA mB
Slide 13 : P. K. BHARTI, I.I.T. KHARAGPUR Q10. A man has fallen into a ditch of width d and two of his friends are slowly pulling him out using a light rope and two fixed pulleys as shown in figure. Show that the force (assumed equal for both the friends) exerted by each friend on the rope increases as the man moves up. Find the force when the man is at a depth h.
Slide 14 : P. K. BHARTI, I.I.T. KHARAGPUR Q1. Given m1 = 5 kg, m2 = 2 kg and F = 1 N. find the acceleration of either block. Describe the motion of m1 if the string breaks but F continues to act. m1 m2 F F
Slide 15 : P. K. BHARTI, I.I.T. KHARAGPUR More on
H C Verma,
IIT-JEE
&
other conceptual problems
Tuesday, June 29, 2010 8:30 PM
Slide 16 : P. K. BHARTI, I.I.T. KHARAGPUR Tomorrow Class
Pseudo Force
&
Constraint Equation
Friday, June 25, 2010 8:30 PM
Slide 17 : P. K. BHARTI, I.I.T. KHARAGPUR © 2007-10 P K Bharti, IIT Kharagpur Subscribe complete presentation from
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