9.5- EXPLOSIONS

Question 1

What happens when two objects fly apart after being initially at rest?

Answer 1

they recoil from each other with equal + opposite amounts of momentum

Question 2

Testing a model explosion

Answer 2

when spring released from one trolley, trolleys A + B push each other apart
blocks positioned so trolleys hit blocks at same moment

Question 3

What is the distance travelled by each trolley to the point of impact with block equal to? (testing a model explosion)

Answer 3

its speed * time taken to travel that distance

Question 4

What is the distance ratio like as the time taken is the same for the two trolleys? (testing a model explosion)

Answer 4

distance ratio same as speed ratio

Question 5

What does the trolleys having equal (+ opposite) amounts of momentum mean? (testing a model explosion)

Answer 5

ratio of their speeds inverse of mass ratio

Question 6

What should the distance ratio equal? (testing a model explosion)

Answer 6

equal to inverse of mass ratio

Question 7

If trolley A travels twice as far as trolley B, what would the mass of trolley A be like? (testing a model explosion)

Answer 7

mass of A must be half of mass B (so they carry away equal amounts of momentum)

Question 8

What is the KE of the two trolleys immediately after they separate from each other like? (testing a model explosion)

Answer 8

equal to energy stored in spring when it was originally compressed

Question 9

What is the total KE of two or more objects that fly apart due to explosion like?

Answer 9

total KE immediately after explosion less than total chemical energy released in explosion as heat, light + sound all carry away energy