Projectile motion
- A bullet is fired from a gun at the speed of 280 m s^-1 in the direction 30^° above the horizontal. The maximum height attained by the bullet is (g=9.8 m s^-2,\ 30^°=0.5) : Answer: 4. 1000 m Maximum height: H=u²sin²θ/2g . H=(280)²(0.5)²/2×9.8=78400×0.25/19.6=1000 m. The answer is 1000 m. 1
- A ball is projected with a velocity, 10\ ms^-1, at an angle of 60° with the vertical direction. Its speed at the highest point of its trajectory will be : Answer: 3. 5√(3)\ ms⁻¹ The angle is measured from the vertical, so the angle with the horizontal is 30^° . At the highest point only the hor... 1
- A car starts from rest and accelerates at 5 m/s^2. At t = 4 s, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at t = 6 s ? (Take g = 10 m/s^2) Answer: 4. 20√(2) m/s, 10 m/s ² Key idea: once the ball is dropped, its horizontal velocity stays equal to the car's velocity at that instan... 1