Students drop a 2 kg object from rest out a window that has a height of 10 m during a lab experiment. The students time the

object to hit the ground and measure 1.2 s. Calculate the

difference between the PE at the top and the KE at the bottom.

a. greater than 75 J

b. less than 25 J

c. between 25 J & 50 J

d. between 50 J & 75 J

a. greater than 75 J

Step-by-step explanation:

Potential Energy at the top = mgh

Mass m = 2kg

g = 9.8m/s^2

height h  = 10m

Potential Energy at the top = 2 * 10 * 9.8

Potential Energy at the top = 196Joules

The object is not moving at the bottom, hence the KE of the body at the bottom is 0Joules

difference between the PE at the top and the KE at the bottom = 196 - 0 = 196Joules

Hence the difference between the PE at the top and the KE at the bottom is greater than 75Joules

solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.

d is the correct answer

step-by-step explanation:

x= 8 because 3x = 3 * 8, and 3*8 = 24