+ 6.3 Quiz (B)
This test/quiz is accepting submissions until Friday, January 29, 2021 at 3:00 pm
Questions 1
Question 1 (1 point)
A roller coaster with a mass of 700 kg has 9000 J of kinetic energy. How fast is going (what is its velocity)?
a
12.85 m/s
b
6.4 m/s
С
5.1 m/s

5.1 m/s

Explanation:

The equation for kinetic energy is KE=1/2m*v2

You plug 9000J into KE and divide 700 in half to plug in for 1/2m.  That gives us 9000=350*v2.  You divide on both sides by 350, leaving us with 25 with a remainder=v2.  The square root of 25 is 5.  5.1.

my exact test question and unit haha

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles