Answer:
mass = 0.14kg
Step-by-step explanation:
kinetic energy (K.E.) = ( m / 2 ) v^2
where,
m = mass ( kg )
K.E. = kinetic energy ( J )
v = velocity ( m / s )
note that the question does not have a velocity factor in it
but, we are just going to use the speed parameter for velocity since they have the same units ( m / s )
from our question,
m = unknown ( but for solution purposes, we will just call it x)
K.E = 3.10J
v = 6.70 m / s
from our formula,
we substitute our values to have;
3.10 = ( x / 2 ) 6.70^2
3.10 = ( x / 2 ) 44.89
when we open the bracket, 44.98 will multiply with x to give
3.10 = 44.89x / 2
we cross multiply to give us
44.89x = 3.10 ( 2 )
44.89x = 6.20
divide through by 44.89 to give us,
44.89x / 44.89 = 6.20 / 44.89
x = 0.14kg