If the statistical analysis shows that the significance level is below the cut off value they have set (either 0.05 or 0.01) they reject the null hypothesis and accept the alternative hypothesis
Answer:
A) heat
Explanation:
As kinetic energy increases, so does the heat energy produced. The faster the molecules move, the more heat that is generated.
Answer:
The no of revolutions rotor turn before coming to rest is 1,601.1943 and time taken is equal to 19.21 seconds
Explanation:
here we know that torque = I×α
α= angular acceleration
I = moment of inertia of hollow disc = m×
given that m=4.37kg
k=0.0710m
torque=1.2Nm


from the above equation we can calculate the angular acceleration of the hollow disc .
since 

from this above equation 
no of revolutions =
= 1,601.1943.
Now to calculate time we know that time = 
so upon calculating we will be getting t=19.21 seconds
Answer:
u= 20.09 m/s
Explanation:
Given that
m = 0.02 kg
M= 2 kg
h= 0.2 m
Lets take initial speed of bullet = u m/s
The final speed of the system will be zero.
From energy conservation
1/2 m u²+ 0 = 0+ (m+M) g h
m u²=2 (m+M) g h
By putting the values
0.02 x u² = 2 (0.02+2) x 10 x 0.2 ( take g=10 m/s²)
u= 20.09 m/s