Definition of a Projectile

Q.

What is range in projectile motion?

Q.

What is the difference between dot product and cross product?

Q. A uniformly charged ring of radius $3a$ and total charge $q$ is placed in $xy-$plane centred at origin. A point charge $q$ is moving towards the ring along the $z-$axis and has speed $v$ at $z=4a$. The minimum value of $v$ such that it crosses the origin is

1. $\sqrt{\frac{2}{m}}{\left(\frac{1}{15}\frac{q^2}{4\pi {\in }_{0}a}\right)}^{1/2}$
2. $\sqrt{\frac{2}{m}}{\left(\frac{2}{15}\frac{q^2}{4\pi {\in }_{0}a}\right)}^{1/2}$
3. $\sqrt{\frac{2}{m}}{\left(\frac{1}{5}\frac{q^2}{4\pi {\in }_{0}a}\right)}^{1/2}$
4. $\sqrt{\frac{2}{m}}{\left(\frac{4}{15}\frac{q^2}{4\pi {\in }_{0}a}\right)}^{1/2}$

Q.

A large number of bullets are fired in all directions with same speed u. What is the maximum area on the ground on which these bullets will spread

1. 

2. 

3. 

4. 

Q. Two boys, first 52 inches tall and second 55 inches tall, are standing at the distances 4.0 m and 5.0 m respectively from an eye. Which boy will appear taller?

1. $\text{First boy}$
2. $\text{Second boy}$
3. $\text{Both will appear of the same size}$
4. $\text{Data insufficient}$

Q.

Define projectile and write two examples.

Q.

Why is the horizontal velocity of projectile constant?

Q. A man of mass 50kg is standing in an elevator. If elevator is moving up acceleration g/3 then work done by normal reaction of floor of elevator on man when elevator moves by a distance 12m is

Q. The energy required to excite an electron from $n=2$ to $n=3$ energy state is $47.2\text{eV}$. The charge number of the nucleus, around which the electron revolving, will be-

1. $20$
2. $15$
3. $10$
4. $5$

Q. a body of mass 2 kg is projected upwards with a velocity 4 metre per second. The kinetic energy of the body just before striking the ground is what?
answer:16J
please explain the answer in detail.

Q. For a projectile on ground, the maximum angle between instantaneous velocity and instantaneous acceleration is _____ and at _______ seconds.

1. ${150}^{\circ },0.8s$
2. ${60}^{\circ },0.8s$
3. ${60}^{\circ },0.4s$
4. ${120}^{\circ },0s$

Q. The range of a projectile at an angle $\theta$ is equal to half of the maximum range if thrown at the same speed. The angle of projection $\theta$ is given by :

1. 
2. 
3. 
4. Insufficient data

Q. If $h_1$ and $h_2$ be the greatest heights in the two paths of projectile for a given range, then the range is given by:

1. $\sqrt{h_1{h}_2}$
2. $\frac{h_1+h_2}{2}$
3. $4\sqrt{h_1{h}_2}$
4. $\frac{2\sqrt{h_1{h}_2}}{h_1+h_2}$

Q. In hydrogen atom, if the difference in the energy of the electron in $n=2$ and $n=3$ orbits is $E.$, then ionization energy of hydrogen atom is $3.6nE.$ The value of $n$ is (integer only)

Q. If a particle is fired vertically upward from the surface of earth and reaches a heightof 6400km the initial velocity of particle: 1) 4km/s 2)2km/s 3)8km/s 4)16km/s

Q.

Assertion: In a plane to plane projectile motion, the horizontal components of velocity remain constant.

Reason: In a plane to plane projectile motion, the horizontal component of acceleration is zero.

1. both assertion and reason are true and reason is the correct explanation of assertion.

2. both assertion and reason are true but reason is not the correct explanation of assertion.

3. assertion is true but reason is false.

4. assertion is false but reason is true.

Q. A particle is projected with initial velocity $\overrightarrow{v}=3\hat{i}+4\hat{j}+12\hat{k}$ & $\overrightarrow{a}$ = $8\hat{i}+6\hat{j}-4\hat{k}$ then path of particle is

1. parabolic
2. not defined as vector in 3D
3. curved but not parabolic
4. straight line

Q.

Assertion: The two projectiles having same time of flight would have same range.

Reason: The two projectiles having same time of flight would have same maximum height.

1. both assertion and reason are true and reason is the correct explanation of assertion.

2. both assertion and reason are true but the reason is not the correct explanation of assertion.

3. assertion is true but reason is false.

4. assertion is false but the reason is true.

Q. Derive the equations of projectile motion.

Q. A body is projected vertically upward with speed vo(Vo Vescape) from surface of earth. The speed of body at h height is (where Ris radius of earth and g is acceleration due to gravity at earths surfa

Q. Two bodies A and B having mass $m$ and $3m$ are connected by a light string as shown in the figure. The observer is on the block B. Find the acceleration of the image of block B as seen by the observer. $($Consider that mass of the observer is negligible and there is no friction between block $A$ and the surface$)$

1. $\frac{3g}{2}$ downwards
2. $\frac{3g}{2}$ upwards
3. $\frac{g}{2}$ upwards
4. $\frac{g}{4}$ downwards

Q.

A projectile is fired with a speed u at an angle $\theta$ above a horizontal field.The coefficient of restitution of collision between the projectile and the field is e.How far from the starting point, does the projectile makes its second collision with the field ?

Q.

The equation of motion of a stone, thrown vertically upwards is , where the $s=ut–6.3t^2$units of $s$ and $t$ are cm and sec. if the stone reaches a maximum height in 3 sec, then $u=$

1. $18.9cm/sec$

2. $12.6cm/sec$

3. $37.8cm/sec$

4. None of these

Q. If two bodies are projected at ${30}^{\circ }$ and ${60}^{\circ }$ respectively with same velocity then

1. Their ranges are same
2. Their times of flight are same
3. All of these
4. Their heights are same

Q.

The velocity at the maximum height of a projectile is half of its initial velocity of projection u. Its range on the horizontal plane is

1. 

2. 

3. 

4. 

Q. State whether an object can move with a constant acceleration but zero velocity. If possible, give an example.

Q.

The path of a projectile is a parabola.

1. True
2. False

Q. a stone is projected vertically upwards from a point on the ground with a velocity of 20ms inverse1.two seconds later another stone is projected fro the same point with the same velocity.when and where will the two stones meet? (g=10ms inverse2)

Q. Establish a relation between range and height

Q.

The initial velocity of a projectile of mass 1 kg is given by $u=(\hat{i}+\sqrt{3}\hat{j})m/s$. What is the time of flight?

1. $\frac{2\sqrt{3}}{5}s$

2. $\frac{\sqrt{3}}{10}s$

3. $\frac{\sqrt{3}}{5}s$

4. $\frac{3\sqrt{3}}{5}s$