Answer:
0.00016 kg
Explanation:
Given:
Power = P = 1.2 × 10⁹ Watts
Power = work done / Time
efficiency = 0.30
Input power = 1.2 × 10⁹ / 0.30 = 4 × 10⁹ W
Energy = 4 × 10⁹ x 60 x 60 = 1.44 x 10¹³ joules
E = m c² , where c is the speed of light and m is the mass.
⇒ mass = m = E / c² = (1.44 x 10¹³) / (3 × 10⁸ )²
= 0.00016 kg
Some guidance notes which may help.To calculate the current flow, Ohm's law can be used. This can be written as current=voltage/resistance, or I=V/R. V is 1.5V.R for the copper wire quoted would be calculated as R = resistivity x length/cross sectional area. The area would be calculated from the formula area = pi x diameter squared/4So, R=resistivity x length divided by (pi x diameter squared/4)Until is the resistivity of copper is known, that's about as far as can be gone.Any further questions, please ask.
The universe is 13.8 billion years old.
Answer:
38.4 m/s
Explanation:
a) at t = 3.2s. 
b) at t = 3.2 + Δt. 
c) As Δt approaches 0. We can find the velocity by the ratio of Δx/Δt
As Δt approaches 0, v = 38.4 + 0 = 38.4 m/s
