to get weight multiply Mass by 9.8
weight =9.8x15=147N
Answer:
To have the same kinetic energy the speed of the marble must be 9 times the speed of rock.
Explanation:
The general formula of kinetic energy is given as follows:

where,
K.E = Kinetic Energy
m = mass of the object
v = speed of the object
So, for the marble and rock to have same kinetic energy, we can write:

<u>Hence, to have the same kinetic energy the speed of the marble must be 9 times the speed of rock.</u>