Answer:
Efficiency = 71%
Explanation:
Given the following data:
Output energy = 250 Joules
Input energy = 350 Joules
To find efficiency;
Substituting into the equation, we have;
Efficiency = 71.43 ≈ 71%
Therefore, the efficiency of the candle is 71 percent.
Answer:
41°
Explanation:
Kinetic energy at bottom = potential energy at top
½ mv² = mgh
½ v² = gh
h = v²/(2g)
h = (2.4 m/s)² / (2 × 9.8 m/s²)
h = 0.294 m
The pendulum rises to a height of above the bottom. To determine the angle, we need to use trigonometry (see attached diagram).
L − h = L cos θ
cos θ = (L − h) / L
cos θ = (1.2 − 0.294) / 1.2
θ = 41.0°
Rounded to two significant figures, the pendulum makes a maximum angle of 41° with the vertical.
