A projectile thrown with an initial velocity of 10 ms^$$-$$1 at an angle $$\alpha$$ with the horizontal, has a range of 5 m. Taking g = 10 ms^$$-$$2 and neglecting air resistance, what will be the estimated value of $$\alpha$$?

A train moves from rest with acceleration $$\alpha$$ and in time t₁ covers a distance x. It then decelerates to rest at constant retardation $$\beta$$ for distance y in time t₂. Then,