A projectile is thrown with an initial velocity $$(a \hat{i}+b \hat{j}) \mathrm{m} / \mathrm{s}$$, where $$\hat{i}$$ and $$\hat{j}$$ are unit vectors along horizontal and vertical directions respectively. If the range of the projectile is twice the maximum height reached by it, then

A particle is performing U.C.M. along the circumference of a circle of diameter $$50 \mathrm{~cm}$$ with frequency $$2 \mathrm{~Hz}$$. The acceleration of the particle in $$\mathrm{m} / \mathrm{s}^2$$ is

If $$\omega_1$$ is angular velocity of hour hand of clock and $$\omega_2$$ is angular velocity of the earth, then the ratio $$\omega_1$$ : $$\omega_2$$ is

The angular displacement of body performing circular motion is given by $$\theta=5 \sin \frac{\pi t}{6}$$. The angular velocity of the body at $$t=3$$ second will be $$\left[\sin \frac{\pi}{2}=1, \cos \frac{\pi}{2}=0\right]$$