Answer:
It requires <u>1.9 seconds</u> to reach maximum height.
Explanation:
As per given question,
Initial velocity (U) =19 m/s
Final velocity (V) = 0 m/s
Maximum height = S
Time taken is "t"
<u>Calculating time taken to reach maximum height:</u>
We know that time taken to reach the maximum height is calculated by using the formula V = U + at
Substitute the given values in the above equation.
Final velocity is “0” as there is no velocity at the maximum height.
t = 1.9 seconds.
The time taken to reach maximum height is <u>1.9</u> seconds.
<u>Calculating maximum height</u>:
Solving the equation we will get the value of S
-361 = -20S
Negative sign cancel both the sides.
S = 18.05 m
Maximum height is 18.05 m .
D is the right answer for this I think
Answer:
t = Δa / v
Explanation:
To know which option is not true, we shall fine a relationship between acceleration (a), velocity (v), time (t) and radius (r). This is illustrated below:
Acceleration can simply be defined as the rate of change of velocity with time. Mathematically, it is expressed as shown below:
Acceleration = change in velocity / time
a = Δv / t ..... (1)
But
Δv = v₂ – v₁
Substitute the value of Δv into equation (1)
a = Δv / t
a = v₂ – v₁ / t ....... (2)
From equation (1), make Δv the subject of the equation.
a = Δv / t
Cross multiply
Δv = at .... (3)
From equation (1), make t the subject of the equation.
a = Δv / t
Cross multiply
at = Δv
Divide both side by a
t = Δv /a ...... (4)
From circular motion, centripetal's force is given by:
F = mv²/r
F = ma꜀
Therefore,
ma꜀ = mv²/r
Cancel out m
a꜀ = v²/r
SUMMARY:
a = Δv / t
a = v₂ – v₁ / t
Δv = at
t = Δv /a
a꜀ = v²/r
Considering the options given in question above, t = Δa / v is not a true statement.
<span>An endothermic reaction will start when the required ΔH energy is received from the environment or solution this is false as the reaction may require energy in excess to start the reaction</span>
Answer:
The correct option is (c).
Explanation:
In the conduction process, the electrons get transferred from one object to the other object. The electrons are freely charged particles. Protons cannot be moved freely.
In the given problem, the given aluminum pie plate is negatively-charged initially. After the conduction process, the plate gets electrically neutral.
It means that the excess of electrons from the aluminum pie plate is removed. Then, the number of electrons and the number of protons becomes equal. The plate becomes electrically neutral.
Therefore, the correct option is "Electrons were removed from the object".
