Question 1 :
A spring 40 mm long is stretched by the application of a force. If 10 N forces required to stretch the spring through 1mm, then work done in stretching the spring through 40 mm is

Question 2 :
<font>A block of mass m slides along the track with kinetic friction µ. A man pulls the block through a rope which makes an angle </font><font face="Symbol, serif"><font></font></font><font> with the horizontal as shown in the figure. The block moves with constant speed V. Power delivered by the man is </font> </p> <p> <img style='object-fit:contain' align="bottom" height="70" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5fc0ef6ce6377b2e815f4d1e" width="189"/> </p>

Question 3 :
<font>A particle of mass m moving with a velocity v strikes a wall and rebounds back. If the magnitude of the velocity is unchanged, the magnitude of force exerted on the wall by the particle during the time of contact (t) will be - </font> </p>

Question 4 :
A body of mass 1000 kg is moving horizontally with a velocity 50m/s. A mass of 250 kg is added. Find the final velocity -<br>

Question 5 :
Power applied to a particle varies with time as <br>P = [3t² - 2t + 1] watts. Where t is time in seconds. Then the change in kinetic energy of particle between time t = 2s to t = 4s is -<br>

Question 6 :
<font>The average energy consumed by a human being in a day is:</font></p>

Question 7 :
A ball is dropped from a height of 20 cm. Ball rebound to a height of 10 cm. What is the loss of energy ?<br>

Question 8 :
<font>Two blocks of masses 2 kg and 1 kg respectively are tied to the ends of a string which passes over a light frictionless pulley. The masses are held at rest at the same horizontal level and then released. The distance traversed by centre of mass in 2 s is -(g = 10 m/s</font>^{<font>2</font>}<font>)</font></p> <p> <img style='object-fit:contain' align="bottom" height="92" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5fc0ef9ba89a512aab21233b" width="93"/> </p>

Question 9 :
A particle of mass 100g is thrown vertically upwords with a speed of 5m/s. The work done by the force of gravity during the time the particle goes up is[2006]<br>

Question 10 :
A particle of mass <em>m</em> is projected with an initial velocity <em>u</em> at angle θ from the ground. What is the work done by gravity during the time it reaches the highest point <em>P</em> is: <br> <img style='object-fit:contain' style="max-width:240px;" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5f16bf5abfef6349df00fcd0"/>

Question 11 :
A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg. The velocity of 18 kg mass is 6 ms^-1. The KE of the other mass is<br>

Question 12 :
ABC is a fixed incline plane with D mid point of AC. Part AD of incline plane is rough such that when a sphere released from A starts rolling, while the part DC is smooth. The sphere reaches the bottom point C, then -<br><img style='object-fit:contain' src='https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5e7d973a236fb948e59c3ace' height='119' width='107' ><br>

Question 13 :
A block of mass <em>m</em> is moving with a constant acceleration <em>a</em> on a rough plane. If the co-efficient of friction between the block and ground is <font face="Symbol">&micro;</font>, the power delivered by the external agent after a time <em>t</em> from the beginning is

Question 14 :
A particle is hanging from a string of length <em>l</em> = 10 m. It is imparted a velocity of 20 m/s at the bottom. The velocity of the particle at its highest point is

Question 15 :
<font>Consider the following statements A and B. Identify the correct choice in the given answers:</font></p> <p align="justify"> <font>A. In a one dimensional perfectly elastic collision between two moving bodies of equal masses, the bodies merely exchange their velocities after collision</font></p> <p align="justify"> <font>B. If a lighter body at rest suffers perfectly elastic collision with a very heavy body moving with a certain velocity, then after collision both travel with same velocity</font></p>

Question 16 :
<font>A truck and a car moving with the same kinetic energy are brought to rest by the application of brakes which provide equal retarding forces. Which of them will come to rest in a shorter distance?</font></p>

Question 17 :
80 railway wagons all of same mass 5 &times; 10³kg are pulled by an engine with a force of 4&times; 10⁵ N. The tension in the coupling between 30^th and 31^st wagon from the engine is:<br>

Question 18 :
A body moves a distance of 10 m along a straight line under the action of a 5 N force. If the work done is 25 J, then angle between the force and direction of motion of the body is -<br>

Question 19 :
The potential energy of a particle of mass 0.1 kg moving along <em>x</em>-axis is given by <em>U</em> = 5<em>x</em><br/> (<em>x</em> – 4), here <em>U</em> is in Joules and <em>x</em> is in meters. Which of the following is incorrect.

Question 20 :
A mass m with velocity u strikes a wall normally returns with the same speed. The change in momentum is<br>

Question 21 :
A body of mass 2 kg is being dragged with a uniform velocity of 2 ms^-1 on a horizontal plane. The coefficient of friction between the body and the surface is 0.2. Work done in 5s is<br>

Question 22 :
<font>The following data is obtained from a computer simulation for a patted baseball with mass 0.145 kg including air resistance. Find the work done by the air on the base ball as it moved from maximum height to back to its position </font> </p> <table width="308"> <tr> <td width="38"><p> <font>t (s)</font></p> </td> <td width="44"><p> <font>x(m)</font></p> </td> <td width="40"><p> <font>y(m)</font></p> </td> <td width="47"><p> <font>v_x(ms^-1)</font></p> </td> <td width="47"><p> <font>v_y(ms^-1)</font></p> </td> </tr> <tr> <td width="38"><p> <font>0</font></p> </td> <td width="44"><p> <font>0</font></p> </td> <td width="40"><p> <font>0</font></p> </td> <td width="47"><p> <font>30</font></p> </td> <td width="47"><p> <font>40</font></p> </td> </tr> <tr> <td width="38"><p> <font>3.05</font></p> </td> <td width="44"><p> <font>70.2</font></p> </td> <td width="40"><p> <font>53.6</font></p> </td> <td width="47"><p> <font>18.6</font></p> </td> <td width="47"><p> <font>0</font></p> </td> </tr> <tr> <td width="38"><p> <font>6.59</font></p> </td> <td width="44"><p> <font>124.4</font></p> </td> <td width="40"><p> <font>0</font></p> </td> <td width="47"><p> <font>12.0</font></p> </td> <td width="47"><p> <font>-30</font></p> </td> </tr> </table>

Question 23 :
A ball of mass 1 kg strikes a wedge of mass 4 kg horizontally with a velocity of 10 m/s. Just after collision, velocity of wedge becomes 4 m/s. Friction is absent everywhere and collision is elastic. Select the correct alternative - <br><img style='object-fit:contain' src='https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5e7d977b25bd3947928ed773' height='81' width='111' ><br>

Question 24 :
<font>A block of mass 2kg is released from A on the track that is one quadrant of a circle of radius 1m. It slides down the track and reaches B with a speed of </font> <img style='object-fit:contain' align="bottom" height="22" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5fc0f4bba89a512aab212e42" width="41"/> <font> and finally stops at C at a distance of 3m from B. The work done against the force of friction is</font></p> <p> <img style='object-fit:contain' align="bottom" height="93" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5fc0f4bba89a512aab212e43" width="190"/> </p>

Question 25 :
<font>A particle of mass m is projected with velocity u at an angle </font><font face="Symbol, serif"><font></font></font><font> with horizontal. During the period when the particle descends from highest point to the position where its velocity vector makes an angle </font><font face="Symbol, serif"><font></font></font><font>/2 with horizontal. Work done by the gravity force is</font></p>