B- lack of control.
the scientists did not have a proper control group.
For each load, Work = (mass) x (gravity) x (distance .
Bigger load: Work = (10 kg) x (9.8 m/s²) x (2 m) = 196 joules .
Smaller load: Work = (5 kg) x (9.8 m/s²) x (4 m) = 196 joules.
The work required is equal in both cases.
The mass ratio of 2:1 is exactly balanced by
the height ratio of 1:2 .
Answer:
Efficiency = 90 %
Wasted energy = 10 %
Explanation:
Since we have the input energy and useful output energy of the electric kettle, the only thing we are required to calculate here is its efficiency. This is gotten from
E = useful output energy/input energy × 100
E = 9/10 × 100 = 90 %
The percentage of wasted energy is
W = wasted energy/input energy × 100
W = 1/10 × 100
W = 10 %
Answer:
The angular velocity at the beginning of the interval is
.
Explanation:
Given that,
Angular acceleration 
Angular displacement 
Angular velocity 
We need to calculate the angular velocity at the beginning
Using formula of angular velocity


Where,
= angular acceleration
= angular velocity
Put the value into the formula



Hence, The angular velocity at the beginning of the interval is
.
Answer:
protons (+ charge) & neutrons (neutral charge)
however protons has a positive charge so it determined what atom it is.