Three particles are moving with constant velocities and v respectively as given in the figure. After some time, if all the three particles are in the same line, then the relation among and v is:
1.
2.
3.
4.
Certain neutron stars are believed to be rotating at about 1 rev/s. If such a star has a radius of 20 km, the acceleration of an object on the equator of the star will be:
1. | \(20 \times 10^8 \mathrm{~m} / \mathrm{s}^2 \) | 2. | \(8 \times 10^5 \mathrm{~m} / \mathrm{s}^2 \) |
3. | \(120 \times 10^5 \mathrm{~m} / \mathrm{s}^2 \) | 4. | \(4 \times 10^8 \mathrm{~m} / \mathrm{s}^2\) |
The angle turned by a body undergoing circular motion depends on the time as given by the equation, . It can be deduced that the angular acceleration of the body is?
1. θ1
2. θ2
3. 2θ1
4. 2θ2
A vector is turned without a change in its length through a small angle The value of and are, respectively:
1. | 0, adθ | 2. | dθ, 0 |
3. | 0, 0 | 4. | None of these |
A particle is moving such that its position coordinates \((x,y)\) are \((2\) m, \(3\) m) at time \(t=0,\) \((6\) m, \(7\) m) at time \(t=2\) s and \((13\) m, \(14\) m) at time \(t=5\) s. Average velocity vector \((v_{avg})\) from \(t=0\) to \(t=5\) s is:
1. | \(\frac{1}{5}\left ( 13\hat{i}+14\hat{j} \right )\) | 2. | \(\frac{7}{3}\left ( \hat{i}+\hat{j} \right )\) |
3. | \(2\left ( \hat{i}+\hat{j} \right )\) | 4. | \(\frac{11}{5}\left ( \hat{i}+\hat{j} \right )\) |
A body is projected with velocity m/s. The time of flight of the body is: [considering x as horizontal and y as vertical axis and g is acceleration due to gravity]
1.
2.
3.
4.
A car moves on a circular path such that its speed is given by v = Kt, where K =constant and t is time. Also given: radius of the circular path is r. The net acceleration of the car at time t will be:
1.
2. 2K
3. K
4.
Raindrops are falling with a speed v vertically downwards and a man is running on a horizontal road with speed u. The magnitude of the velocity of the raindrops with respect to the man is:
1. v - u
2. v + u
3. \(\sqrt{\text{v}^2 + \text{u}^2 \over 2}\)
4. \(\sqrt{\text{v}^2 + \text{u}^2}\)
The equation of trajectory of a projectile is given by y = x - 10. Its speed of projection is: (g = 10 m/)
1. 1 m/s
2. 2 m/s
3. 3 m/s
4. 4 m/s
A particle is thrown obliquely at \(t=0\). The particle has the same K.E. at \(t=5\) seconds and at \(t=9\) seconds. The particle attains maximum altitude at:
1. \(t=6\) s
2. \(t=7\) s
3. \(t=8\) s
4. \(t=14\) s