2. Many factors have to be taken into account to achieve a successful rocket launch, maintain a stable orbit and return to Earth

Galileo's analysis of projectile motion Describe Galileo’s analysis of projectile motion

Describe the trajectory of an object undergoing projectile motion within the Earth’s gravitational field in terms of horizontal and vertical components

Describe Galileo’s analysis of projectile motion.

v x = u x + a x t v x 2 = u x 2 + 2a x  x  x = u x t + ½ a x t 2 v x = u x v x 2 = u x 2  x = u x t v y = u y + a y t v y 2 = u y 2 + 2a y  y  y = u y t + ½ a y t 2 solve problems and analyse information to calculate the actual velocity of a projectile from its horizontal and vertical components using: v = u + at v 2 = u 2 + 2as s = ut + ½ at 2 (N.B. change to component versions)

The trajectory of a projectile in the Earth’s gravitational field is parabolic, provided that air resistance is ignored and the acceleration due to gravity is uniform. This complex motion can be analysed by considering its horizontal and vertical components at particular instances during the flight. The horizontal motion of the projectile is a constant velocity (air resistance is assumed negligible). Its vertical motion is changing all the time due to the effect of gravity, which causes the projectile to accelerate at 9.8 m s -2 downwards. (NSW HSC on-line) Describe the trajectory of an object undergoing projectile motion within the Earth’s gravitational field in terms of horizontal and vertical components

15 m 5 m/s

15 m 5 m/s

Perform a first-hand investigation, gather information and analyse data to calculate initial and final velocity, maximum height reached, range, and time of flight of a projectile, for a range of situations by using simulations, data loggers and computer analysis Projectile motion Experiments Marble launcher Data logger for launch velocity Video analysis Stroboscopic photography Projectile motion simulation Cannon

Describe first-hand investigations you conducted to investigate initial and final velocity, maximum height reached, range, and time of flight of a projectile, for a range of situations by using simulations, data loggers and computer analysis

Explain the concept of escape velocity in terms of the: – gravitational constant – mass and radius of the planet Outline Newton‘s concept of escape velocity (see website)

Escape velocity is the velocity required to just escape the gravitational pull of the planet. It depends on the ratio of the mass and radius of the planet. The formula shows that the larger the mass/radius ratio of the planet, the greater the escape velocity is. i.e. if 2 planets had the same radius, the planet with the larger mass would have a greater escape velocity. Outline Newton‘s concept of escape velocity (Jacaranda p.27) Explain the concept of escape velocity in terms of the: – gravitational constant – mass and radius of the planet Outline Newton‘s concept of escape velocity