In an exothermic reaction, there is a transfer of energy to the surroundings in the form of heat energy. The surroundings of the reaction will experience an increase in temperature. Many types of chemical reactions are exothermic, including combustion reactions, respiration & neutralization reactions of bases & acids.
Answer:
The current in the circuit at a time interval of τ seconds after the switch has been closed is 0.123 A
Explanation:
The time constant for an R and C in series circuit is given by τ = RC.
R = 3000 ohms, C = 0.5 × 10⁻⁶ F = 5.0 × 10⁻⁷ F
τ = 3000 × 5 × 10⁻⁷ = 0.015 s
The voltage across a capacitor as it charges is given be
V(t) = Vs (1 - e⁻ᵏᵗ)
where k = 1/τ
At the point when t = τ, the expassion becomes
V(t = τ) = 1000 (1 - e⁻¹) = 0.632 × 1000 = 632 V
Current flows as a result of potential difference,.
Current in the circuit at this time t = τ is given by
I = (Vs - Vc)/R
Vs = source voltage = 1000 V
Vc = Voltage across the capacitor = 632 V
R = 3000 ohms
I = (1000 - 632)/3000 = 0.123 A
It does not it when put in the freezer it freezes the steam
Answer:

Explanation:
Given;
The operational pressure of the cooker, 
area of the opening, 
- We know that the gauge pressure is measured with respect to the atmospheric pressure. As the atmospheric pressure acts on all the components of the system being observed so, we only need to counter the gauge pressure.
As the petcock sits on the opening of the cross-section so, it balances the built-in pressure due to its weight.
<u>Hence:</u>

where:
mass of the petcock
acceleration due to gravity


Answer:
Explanation:
If Tim jogs a distance of 7.2 km to the west and then he turns south and jogs 1.4 km, the resultant displacement of Tim is calculated using the pythagoras theorem as shown;
R² = 7.2²+1.4²
R² = 51.84+1.96
R² = 53.8
R = √53.8
R = 7.33 km
Hence the resultant of Tim's jog back to the beginning is 7.33km