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## Momentum

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**key ideas about momentum**• Momentum is the amount of m an object has • Momentum is to do with the m and the v • of an object • In an explosion the momentum of an object moving • to the l is equal to the of the object • which moves to the r Fill in the answers and then click to check them**key ideas about momentum**otion • Momentum is the amount of m_____ an object has • Momentum is to do with the m___ and the v______ • of an object • In an explosion the momentum of an object moving • to the l____ is equal to the __________ of the object • which moves to the r_____ ass elocity eft momentum ight**key words for the momentum topic**TUM NO MEM RE COF CITY OF VEL SAMS STREEM ERP DESCON OG RI SMALK POXLESION NO NANC LALB LE RIF TUBLLE is the amount of motion an object has is measured in Newtons is how fast it moves in a certain direction the amount of material measured in kilograms the unit for velocity the unit for mass when stationary objects go in opposite directions old fashioned gun spherical object leaving the previous gun modern gun which you rest on the shoulder to fire fired by the gun above Fill in the answers and then click to check them**key words for the momentum topic**momentum force velocity mass Metres per second kilograms explosion cannon ball rifle bullet is the amount of motion an object has is measured in Newtons is how fast it moves in a certain direction the amount of material measured in kilograms the unit for velocity the unit for mass when stationary objects go in opposite directions old fashioned gun spherical object leaving the previous gun modern gun which you rest on the shoulder to fire fired by the gun above Fill in the answers and then click to check them**How much momentum do the following object have?**1 A 700kg car travelling at 10 m/s 2 A 1500kg van travelling at 5m/s 3 A mini travelling at 20m/s with a mass of 800kg 4 A 45kg person running at 4m/s Momentum = x = Momentum = x = Momentum = x = Momentum = x = click for the answers**How much momentum do the following object have?**1 A 700kg car travelling at 10 m/s 2 A 1500kg van travelling at 5m/s 3 A mini travelling at 20m/s with a mass of 800kg 4 A 45kg person running at 4m/s Momentum = 700 x 10 = 7000 kgm/s Momentum = 1500 x 5 = 7500 kgm/s Momentum = 800 x 20 = 16 000 kgm/s Momentum = 45 x 4 = 180 kgm/s**cannonball moves this way**with a high velocity Cannon moves this way more slowly as it recoils from the explosion**Velocity as it leaves the cannon = 400m/s**Mass of cannon ball =? Momentum = Momentum of of ball cannon Recoil velocity = 8m/s Mass = 100kg mass x velocity = mass x velocity of the ball of the cannon ? X 400 = 100 x 8 ? X 400 = 800 ? = 800/400 = 2kg**V**Now do your own calculation Fill in the answers and then click to check them Velocity as it leaves the cannon = 500m/s Mass of cannon ball =? Momentum = Momentum of of ball cannon Recoil velocity = 10m/s Mass = 50kg mass x velocity = mass x velocity of the ball of the cannon ? x = x ? x = ? = =**Velocity as it leaves the cannon = 500m/s**Mass of cannon ball =? Momentum = Momentum of of ball cannon Recoil velocity = 10m/s Mass = 50kg mass x velocity = mass x velocity of the ball of the cannon ? X 500 = 50 x 10 ? X 500 = 500 ? = 500/500 = 1kg**The moving ball hits the stationary ball**• The stationary ball moves off • If the first ball stops • The second ball gains all the momentum of the first ball**v**2m/s 5kg 5kg Momentum of first ball = momentum of second ball (before collision) (after collision) 5kg x 2m/s = 5kg x v So v = 2m/s In the second case the first ball has more mass but the same idea applies Momentum of first ball = momentum of second ball (before collision) (after collision) 8kg x 2m/s = 4kg x v So v = 4m/s v 2m/s 8kg 4kg**Now try these**v 3m/s 12kg 12kg Momentum of first ball = momentum of second ball (before collision) (after collision) x = x v So v = In the second case the first ball has more mass but the same idea applies Momentum of first ball = momentum of second ball (before collision) (after collision) x = x v So v = Now click for the answers v 5m/s 12kg 4kg**Now try these**v 3m/s 12kg 12kg Momentum of first ball = momentum of second ball (before collision) (after collision) 12 x 3 = 12 x v So v = 3m/s In the second case the first ball has more mass but the same idea applies Momentum of first ball = momentum of second ball (before collision) (after collision) 12 x 5 = 4 x v So v = 15m/s v 5m/s 12kg 4kg**More collisions**Higher level**Momentum before the collision = Momentum after the**collision (of the single ball) ( of both balls)**Momentum before the collision = Momentum after the**collision (of the single ball) ( of both balls) • 3 x 8 = (3+3) v • = 6 x v • So v = 24/6 • v = 4m/s v 8 m/s 3kg 3kg 3kg**Another example**Momentum before the collision = Momentum after the collision (of the single ball) ( of both balls) 3 x 9 = (6+3) v 27 = 9 x v So v = 27/9 v = 3m/s V 9 m/s 6kg 3kg 3kg**Now try this one yourself**Momentum before the collision = Momentum after the collision (of the single ball) ( of both balls) = x v x = x v So v = Click for the answer V 10 m/s 1kg 4kg 4kg**Momentum before the collision = Momentum after the**collision (of the single ball) ( of both balls) 3 x 9 = (6+3) v 27 = 9 x v V = 3m/s V 9 m/s 6kg 3kg 3kg**Collisions and safety**Higher level**Stopping quickly is dangerous because**a large force is felt for a short time The crumple zone on this car allows the car to change shape slowly so that a smaller force is felt for a longer time**Hitting the windscreen in a car crash means that a**large force is felt for a short time which can cause severe injuries for the driver Hitting the airbag in a car crash means that a smaller force is felt for a longer timewhich is Much safer for the driver Force (N) Which line represents the air bag? The blue line The red line shows a big force for a short time The blue line shows a smaller force acting over a longer time time (s)