A 3 kg ball strikes a heavy rigid wall with a speed of 10 m/s at an angle of 60◦. It gets reflected with the same speed and angle as shown here. If the ball is in contact with the wall for 0.20 s, what is the average force exerted on the ball by the wall?

A satellite in a force free space sweeps stationary interplanetary dust at a rate (dM/dt) = αv. The acceleration of satellite is

Physical independence of force is a consequence of

A particle of mass m is moving with a uniform velocity $v_1$. It is given an impulse such that its velocity becomes $v_2$. The impulse is equal to

A 600 kg rocket is set for a vertical firing. If the exhaust speed is 1000 $ms^{−1}$, the mass of the gas ejected per second to supply the thrust needed to overcome the weight of rocket is

trial chatgpt codes

\[ \frac{F_{\text{electric}}}{F_{\text{gravity}}}\]



\[ \frac{F_{\text{electric}}}{F_{\text{gravity}}} = \frac{\frac{1}{4\pi \varepsilon_0} \cdot \frac{q_1 q_2}{r^2}}{G \cdot \frac{m_1 m_2}{r^2}} = \frac{(9 \times 10^9) \cdot \frac{(1.6 \times 10^{-19})(1.6 \times 10^{-19})}{r^2}}{(6.67 \times 10^{-11}) \cdot \frac{(1.67 \times 10^{-27})(9.11 \times 10^{-31})}{r^2}} = 2.4 \times 10^{39} \] \[ I = m_1 x^2 + m_2 (L - x)^2 \] \[ \frac{dI}{dx} = m_1 \cdot 2x + m_2 \cdot 2(L - x)(0 - 1) \] \[ \text{Minimum when } \frac{dI}{dx} = 0 \] \[ m_1 \cdot 2x = m_2 \cdot 2(L - x) \] \[ m_1 \cdot 2x = m_2 \cdot 2L - m_2 \cdot 2x \] \[ (m_1 + m_2) \cdot 2x = m_2 \cdot 2L \] \[ \Rightarrow x = \frac{m_2 L}{m_1 + m_2} \] 

\[ \frac{\Delta L}{L} = ? \] \[ \text{Given: } \text{Hypotenuse } = L + \Delta L, \quad \text{Opposite side } = x \] Using Pythagoras’ Theorem: \[ L^2 + x^2 = (L + \Delta L)^2 \] \[ L^2 + x^2 = \left( L \left(1 + \frac{\Delta L}{L} \right) \right)^2 \] \[ L^2 + x^2 = L^2 \left(1 + \frac{\Delta L}{L} \right)^2 \] Divide both sides by \( L^2 \): \[ 1 + \frac{x^2}{L^2} = \left(1 + \frac{\Delta L}{L} \right)^2 \] \[ \sqrt{1 + \frac{x^2}{L^2}} = 1 + \frac{\Delta L}{L} \] Using the approximation \( \sqrt{1 + x} \approx 1 + \frac{x}{2} \) for small \( x \), we get: \[ 1 + \frac{x^2}{2L^2} \approx 1 + \frac{\Delta L}{L} \] \[ \Rightarrow \frac{\Delta L}{L} \approx \frac{x^2}{2L^2} \] \[ \boxed{\frac{\Delta L}{L} = \frac{x^2}{2L^2}} \]



\[ \sum F = ma \]\[ 100 - \mu mg = ma \] \[ 100 - (0.5)(10)(10) = (10)a \] \[ 50 = 10\hspace{2mm}a \] \[ a = 5 \, \text{m/s}^2 \]

In carbon monoxide molecule, the carbon and the oxygen atoms are separated by a distance 1.12 × $10^{−10}$m. The distance of the centre of mass, from the carbon atom is

In carbon monoxide molecule, the carbon and the oxygen atoms are separated by a distance 1.12 × 10−10 m. The distance of the centre of mass, from the carbon atom is

(a) $0.64 × 10^{−10} m$

(b) $0.56 × 10^{−10} m$

(c) $0.51 × 10^{−10} m$

(d) $0.48 × 10^{−10} m$

[NEET 1997]

\[M\; r_{cm}=m_1 \; r_1 + m_2 \; r_2\]

\[\left (12u+16u \right) \; x = 12u \; (0) + 16u \left (1.12\times 10^{-10}\right)\]

\[x=0.64 \times 10^{-10}m\]








12P07B RL RC Charging Discharging Transient Currents

 


Change the resistance value R and the Capacitance value C in the slider
to study how the curve changes, 
to observe how quickly charging and discharging are happening,
to understand what is the time constant.





Change the resistance value R and the Inductor value L in the slider
to study how the curve changes, 
to observe how quickly charging and discharging are happening,
to understand what is the time constant.


Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t1. On other days, if she remains stationary on the moving escalator. then the escalator takes her up in time t2. The time taken by her to walk up on the moving escalator will be:

 Problem 7. Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t1. On other days, if she remains stationary on the moving escalator. then the escalator takes her up in time t2. The time taken by her to walk up on the moving escalator will be: [NEET 2017]

(a) t1t2

t2−t1

(b) t1t2

t2+t1

(c) t1 − t2

(d) t1+t2

2





A particle covers half of its total distance with speed $v_1$ and the rest half distance with speed $v_2$. Its average speed during the complete journey is

 Problem 6. A particle covers half of its total distance with speed $v_1$ and the rest half distance with speed $v_2$. Its average speed during the complete journey is [NEET 2011M]

(a) $\frac {v_1 v_2}{v_1 + v_2}$

(b) $\frac {2 v_1 v_2}{v_1 + v_2}$ 

(c) $\frac {2 v_1^2 v_2^2}{v_1^2 + v_2^2}$

(d) $\frac {v_1 + v_2}{2}$

\[Avg. Speed = \frac {Total \; distance}{Total \; time}\]

\[ = \frac {\frac{d}{2} + \frac {d}{2}}{\frac{d/2}{v_1}+\frac{d/2}{v_2}}\]

\[=\frac{2 v_1 v_2}{v_1+v_2}\]


A car moves from X to Y with a uniform speed $v_u$ and returns to Y with a uniform speed $v_d$. The average speed for this round trip is

 Problem 5. A car moves from X to Y with a uniform speed $v_u$ and returns to Y with a uniform speed $v_d$. The average speed for this round trip is [NEET 2007]

(a) $\sqrt{v_u v_d}$

(b) $\frac{v_d v_u}{v_d + v_u}$

(c) $\frac{v_d + v_u}{2}$

(d) $\frac{2 v_d v_u}{v_d + v_u}$