Net Force

Q.

A machine gun fires a bullet of mass 40 g with a velocity of $1200m{s}^{-1}$. The gun can exert a maximum force of 144 N on the bullet. How many bullets can he fire per second at the most?

1. Two

2. One

3. Four

4. Three

Q. 102.when one metre, one kg and one minute taken as fundamental units, the magnitude of a force is 36 units. What is the value of this force on cgs system?

Q. A body of mass 5 kg is acted upon by two perpendicular forces 8 N and 6 N. Give the magnitude and direction of the acceleration of the body.

Q. 14.A wooden is taken to the bottom of a lake of water and then released. It rises up with a 1-constant acceleration 2-decreasing acceleration 3-constant velocity 4-decreasing velocity

Q.

Free body diagram of a situation is shown below. The net force is known, however, the magnitude of few of the forces is not known. The magnitude of the unknown forces C and D will be:

1. C = 40 N, D = 60 N

2. C = 40 N, D = 100 N

3. C = 40 N, D = 80 N

4. C = 40 N, D = 80 N

Q.

A pulley which is fixed to the ceiling of an elevator car carries a thread whose ends are attached to the masses $m_1$ and $m_2$. The car starts going up with an acceleration $a_0$. Assuming the masses of the pulley and the thread as well as the friction to be negligible, find:

Match the given columns according to the options where,

is the acceleration of the load $m_1$ relative to the ground.

Is the acceleration of the load $m_1$ relative to the elevator car.

is the force exerted by the pulley on the ceiling of the car. Given, $m_1>m_2$

(i) $a_{\frac{m_1}{g}}$ (u) $\frac{4m_1{m}_2(a_0+g)}{(m_1+m_2)}$

(ii)$a_{\frac{m_1}{elevator}}$ (v) $\frac{2a_1{m}_1-g{m}_2}{(m_1+m_2)}$

(iii)$F_{pulleyoncieling}$ (w) $\frac{2a_0{m}_2-g(m_1-m_2)}{(m_1+m_2)}$

1. (i) - (w); (ii) - (x); (iii) - (u)

2. (i) - (u); (ii) - (w); (iii) - (v)

3. (i) - (v); (ii) - (w); (iii) - (x)

4. (i) - (x); (ii) - (w); (iii) - (u)

Q. 46. Drums of oil are carried in a truck.if a constant acceleration is applied on the truck the surface of oil in drum will 1.remain affected 2.rise towards backward direction And why? Click here to view details:

Q. The nearest star to our solar system is 4.29 light years away. How much is this distance in terms of parsecs? How much parallax would this star (named Alpha Centauri) show when viewed from two locations of the Earth six months apart in its orbit around the Sun ?

Q. A uniform rod pivoted at its upper end hangs vertically. It is displaced through an angle of 60 degrees and then released. Find the magnitude of the force acting on a particle of mass dm at its tip when the rod makes an angle of 37 degrees with the vertical

Q. A ball dropped from an elevator moving upward with acceleration a by a boy standing in it .The acceleration of Ball with respect to (Take upward direction positive) 1)boy is -g 2)boy is -(g+a) 3) ground is -g 4)both (2)&(3)

Q. The vector sum of two forces is perpendicular to their vector difference .in that case, the forces 1)are equal to each other 2)are equal to each other in magnitude 3)are not equal to each other in magnitude 4)cannot be predicte

Q. a uniform bar of mass M is and lenght l is carried upward by applying a force F on its upper end. what is force at dis†an ce X from its lower end

Q. Arrangement of two blocks as shown in the figure.The net force acting on 1Kg and 2kg blocks are respectively

Q. Two parallel forces F1 AND F2 are applied perpendicular to a massless rod oflength l at ends of rod.Find the value and position of third force to be applied on rod to keep it in equilibrium state?

Q. 13. A horizontal force of 200 N pulls two masses 4 kg and 6 kg (lying on a frictionless surface) connected by a light string. T is the tension in string connected between them when pull is applied on 4 kg block. If the pull is applied on 6 kg block instead of 4 kg block, then tension in the string will be 4T 2T (2) 3 3 37 (3) (4) T

Q.

A string of negligible mass going over a clamped pulley of mass m supports a block of mass M as shown in the figure. The force on the pulley by the clamp is given by

1. 

2. 

3. 

4. 

Q. (b) An applied unbalanced force causes a change in momentum. explain

Q. when a body is spinning on its axis in absence of any external torque , then choose the wrong statement 1) w can be changed by keeping L same 2) L can be changed by keeping w same 3) I cab be changed by keeping L same 4) I and w both can be changed by keeping L same

Q. A box ${}^{\prime }{A}^{\prime }$ is lying on the horizaontal floor of the compartment of a train running along horizontal rails from left to right. At time ${}^{\prime }{t}^{\prime }$, it decelerates. then the reaction $R$ by the floor on the box is given best by

1. 
2. 
3. 
4. 

Q. In a particular system the units of length mass and time are chosen to be 10 cm , 10 g , and 0. 1 s respectovely. The unit of force in this system will be equivalent to : (1) 0.1 N (2 ) 1 N (2) 10 N (4) 100 N.

Q. consider an object of mass m connected with an ideal spring of spring constant K.show that the speed and the KE will be maximum at equilibrium position.get an expression for the maximum speed.

Q. A projectile of mass m is fired into a liquid at an angle θ_{} with an initial velocity v as shown. If the liquid develops a frictional or drag resistance on the projectile which is proportional to its velocity, i.e., F =-kv where k is a positive constant, determine the x and ycomponents of its velocity at any instant.Also find the maximum distance x_{ma} that it travels?

Q. 1.A thin wire of length L and uniform linear mass density p is bent into a circular loop with centre at O. The moment of inertia of the loop along the axis which is tangent to loop.

Q. A point mass is attached with a massless string of length l, whose other end is fixed and free to rotate in a vertical plane. At the lowest point it is given that a horizontal velocity √4gl. Acceleration of the particle at the instant when the body i is horizontal

Q.

If no resultant force acts on a body then the body will be in

1. none of the above

2. earlier state (no change in state)

3. motion

4. rest

Q. Ten coins are placed on top of each other on a horizontal table. If the mass of each coin is $10\text{gm}$, what is the magnitude and direction of the force on the 7th coin (counted from the bottom) due to all the coins above it? Take $g=10m/s^2$

1. 0.3 N downwards
2. 0.3 N upwards
3. 0.7 N downwards
4. 0.7 N upwards

Q. 37. A block of mass media is stationary on a rough inclined plane making an angle Θ with the horizontal. Find the contact force between block and the plane

Q. ntTwo weights W1 and W2 are suspended to the two strings on an ntfrictionless pulley. When the pulley is pulled up with an acceleration 9, then the tension in the string is :n nt(a)4W1W2 /W1 +W2n ntn nt(b)W1W2/W1 + W2n ntn nt(c)2W1W2/W1 + W2n ntn nt(d)W1 + W2/2n ntn

Q. 38. A block of mass m is placed on a smooth wedge of inclination theta . The whole system is accelerate horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block has a magnitude.

Q. As a swinging pendulum passes through its lowest point, in which direction does the net force act?

1. Only in the angular direction
2. Only in a radial direction
3. In both angular and radial directions
4. There is zero net force at the equilibrium point