Answer:
192000 J
Step-by-step explanation:
k = 1/2 mv²
48000 = 1/2 x m x (20)²
48000 = 200m
m = 240 kg
new k
k = 1/2 x 240 x 40²
k = 192000 J
It's 
which gives 5.23 times increase in 10 years, so 523% of oryginal price
Q.q i dunno , seems like he doesnt have enough money with the 6 deposites of 35.5 = 213 if you add the deposists to 420+213=633 , and he needs 4 checks of 310 eaach , he could only write 2 checks , so i suppose theirs not enough information to accumulate a answer
