The following are four different relations about displacement, velocity and acceleration for the motion of a particle in general.
(a) | \(v_{a v}=1 / 2\left[v\left(t_1\right)+v\left(t_2\right)\right]\) |
(b) | \(v_{{av}}={r}\left({t}_2\right)-{r}\left({t}_1\right) / {t}_2-{t}_1\) |
(c) | \(r=1 / 2\left[v\left(t_2\right)-v\left(t_1\right)\right]\left({t}_2-{t}_1\right)\) |
(d) | \({a}_{{av}}=v\left({t}_2\right)-v\left({t}_1\right) / {t}_2-{t}_1\) |
The incorrect options is/are:
1. | (a) and (d) only | 2. | (a) and (c) only |
3. | (b) and (c) only | 4. | (a) and (b) only |
For a particle performing uniform circular motion,
(a) | the magnitude of particle velocity (speed) remains constant. |
(b) | particle velocity is always perpendicular to the radius vector. |
(c) | the direction of acceleration keeps changing as the particle moves. |
(d) | angular momentum is constant in magnitude but direction keeps changing. |
Choose the correct statement/s:
1. | (c), (d) | 2. | (a), (c) |
3. | (b), (c) | 4. | (a), (b), (c) |
Two particles are projected in the air with speed \(v_0\), at angles \(\theta_1\) and \(\theta_2\) to the horizontal, respectively. If the height reached by the first particle is greater than that of the second, then:
(a) | the angle of the projection: \(\theta_1>\theta_2\) |
(b) | the time of flight: \(T_1>T_2\) |
(c) | the horizontal range: \(R_1>R_2\) |
(d) | the total energy: \(U_1>U_2\) |
Choose the correct option:
1. (a), (c), (d)
2. (a), (c)
3. (b), (c), (d)
4. (a), (b)
A particle slides down a frictionless parabolic track starting from rest at point \(A\). Point \(B\) is at the vertex of the parabola and point \(C\) is at a height less than that of point \(A\). After \(C\), the particle moves freely in the air as a projectile. If the particle reaches the highest point at \(P\), then,
1. | kinetic energy at \(P\) = kinetic energy at \(B\) |
2. | height at \(P\) = height at \(A\) |
3. | total energy at \(P\) = total energy at \(A\) |
4. | time of travel from \(A\) to \(B\) = time of travel from \(B\) to \(P\) |
In a two-dimensional motion, instantaneous speed \(v_0\) is a positive constant. Then which of the following is necessarily true?
1. | The acceleration of the particle is zero. |
2. | The acceleration of the particle is increasing. |
3. | The acceleration of the particle is necessarily in the plane of motion. |
4. | The particle must be undergoing a uniform circular motion. |
In a two-dimensional motion, instantaneous speed \(v_0\) is a positive constant. Then which of the following is necessarily true?
1. | The average velocity is not zero at any time. |
2. | The average acceleration must always vanish. |
3. | The displacements in equal time intervals are equal. |
4. | Equal path lengths are traversed in equal intervals. |
The horizontal range of a projectile fired at an angle of \(15^\circ\) is \(50~\text m.\) If it is fired with the same speed at an angle of \(45^\circ,\) its range will be:
1. \(60~\text m\)
2. \(71~\text m\)
3. \(100~\text m\)
4. \(141~\text m\)
A person is sitting in a traveling train and facing the engine. He tosses up a coin and the coin falls behind him. It can be concluded that the train is:
1. Moving forward and gaining speed.
2. Moving forward and losing speed.
3. Moving forward with uniform speed.
4. Moving backward with uniform speed.
For a particle performing uniform circular motion, choose the correct statement(s) from the following:
1. Magnitude of particle velocity (speed) remains variable.
2. Particle velocity remains directed parallel to radius vector.
3. Direction of acceleration keeps changing as particle moves.
4. Angular momentum is constant in magnitude but direction keeps changing.
The horizontal range of a projectile fired at an angle of 15o is 50 m. If it is fired with the same speed at an angle of 45o, its range will be:
1. 60 m
2. 71 m
3. 100 m
4. 141 m