Answer:
Explanation:
Energy stored in a capacitor
= 1/2 C₁V²
capacity of a capacitor
c = εK A / d
k is dielectric and d is distance between plates .
When the distance between the plates is halved and then filled with a dielectric (κ = 4.3)
capacity becomes 4.3 x 2 times
New capacity
C₂ = 8.6 C₁
Energy of modified capacitor
1/2 C₂ V²= 1/2 x 8.6 c x V²
Energy becomes
8.6 times.
Energy stored = 8.6 x 10⁻⁴ J
Option B: acid+base->water+salt is the equation represents a neutralization reaction.
We have to use the equation speed=distance/time.
We want the average speed in second so we have to change the minutes into seconds. We can do this by multiplying the minutes by 60 (60seconds in 1 minute). 60x1.4= 84 seconds.
Speed=distance/time, distance is 82 and time is 84 so speed=82/84
Average speed = 0.98ms^-1 (2dp)
Answer:
a) Δx = t 0.05 + 0.5
, Δx = 0.5 cm, b) Do not present any problem
Explanation:
The kinematic equation for constant speed is
v = x / t
x = v t
a) the uncertainty can be calculated with
Δx = dx /dv Δv + dx /dt Δt
Δx = t Δv + v Δt
Speed is
v = (50.00 ± 0.05) cm / s
The most common uncertainty for the time of Δt = 0.01 s
We replace
Δx = t 0.05 + 50 0.01
Δx = t 0.05 + 0.5
We must know the time to have an explicit value, if we assume that the measure was t = 1s
Δx = 0.5 cm
b)
Do not present any problem since its value is not very small, we must take as soon as the quantum effects and the velocity are not so high that we must take into account the relativistic effects
Answer:
Graph B represents correct graph for velocity time
Explanation:
Initially the object is dropped under the influence of constant force due to gravity
So here we can say its acceleration is constant due to gravity
hence here the velocity will increase downwards due to gravity and it is given as
now when it enters into the pool an upward force of same magnitude will act on it
so net force on it is
so here we will have no acceleration and it will move with constant speed after that
so here correct graph is
Graph B
