Answer:
The time is 1.8s
Explanation:
The ball droped, will freely fall under gravity.
Hence we use free fall formula to calculate the time by the ball to hit the ground

Where h is the height from which the ball is droped, g is the acceleration due to gravity that acted on the ball, and t is the time taken by the ball to hit the ground.
From the question,
h=16m
Also, let take

By substitution we obtain,


Diving through by 9.8


square root both sides, we obtain


Answer:
Thus, the payback time for cavity wall insulation is 7.5 years
Answer:
a)Q=71.4 μ C
b)ΔV' = 10.2 V
Explanation:
Given that
C ₁= 8.7 μF
C₂ = 8.2 μF
C₃ = 4.1 μF
The potential difference of the battery, ΔV= 34 V
When connected in series
1/C = 1/C ₁ + 1/C₂ + 1/C₃
1/ C= 1/8.4 +1 / 8.4 + 1/4.2
C=2.1 μF
As we know that when capacitor are connected in series then they have same charge,Q
Q= C ΔV
Q= 2.1 x 34 μ C
Q=71.4 μ C
b)
As we know that when capacitor are connected in parallel then they have same voltage difference.
Q'= C' ΔV'
C'= C ₁+C₂+C₃ (For parallel connection)
C'= 8.4 + 8.4 + 4.2 μF
C'=21 μF
Q'= C' ΔV'
Q'=3 Q
3 x 71.4= 21 ΔV'
ΔV' = 10.2 V
Answer:
Explanation:
heat lost by water will be used to increase the temperature of ice
heat gained by ice
= mass x specific heat x rise in temperature
1 x 2090 x t
heat lost by water in cooling to 0° C
= mcΔt where m is mass of water , s is specific heat of water and Δt is fall in temperature .
= 1 x 2 x 4186
8372
heat lost = heat gained
1 x 2090 x t = 8372
t = 4°C
There will be a rise of 4 degree in the temperature of ice.
Answer:
Heliocentrism is the astronomical model in which the Earth and planets revolve around the Sun at the center of the Universe.
Explanation: