Answer : The half-life of this substance will be, 45 minutes.
Explanation :
First we have to calculate the value of rate constant.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = ?
t = time passed by the sample = 90.3 min
a = initial amount of the reactant = 400
a - x = amount left after decay process = 100
Now put all the given values in above equation, we get
Now we have to calculate the half-life of substance, we use the formula :
Therefore, the half-life of this substance will be, 45 minutes.
Answer:
Because of the presence of air resistance
Explanation:
When an object is in free fall, ideally there is only one force acting on it:
- The force of gravity, W = mg, that pushes the object downward (m= mass of the object, g = acceleration of gravity)
However, this is true only in absence of air (so, in a vacuum). When air is present, it exerts a frictional force on the object (called air resistance) with upward direction (opposite to the motion of free fall) and whose magnitude is proportional to the speed of the object.
Therefore, it turns out that as the object falls, its speed increases, and therefore the air resistance acting against it increases too; as a result, the at some point the air resistance becomes equal (in magnitude) to the force of gravity: when this happens, the net acceleration of the object becomes zero, and so the speed of the object does not increase anymore. This speed reached by the object is called terminal velocity.
Answer:
the current is 3.5 A
Explanation:
The computation of the current is shown below:
As we know that
Current [A] = Electrical power [W] ÷ Potential difference [V]
Now convert KW TO W = × 1000
So, the current is
= 800W ÷ 230V
= 3.5 A
Hence, the current is 3.5 A
(a) 3.5 Hz
The angular frequency in a spring-mass system is given by
where
k is the spring constant
m is the mass
Here in this problem we have
k = 160 N/m
m = 0.340 kg
So the angular frequency is
And the frequency of the motion instead is given by:
(b) 0.021 m
The block is oscillating up and down together with the upper end of the spring. The block will lose contact with the spring when the direction of motion of the spring changes: this occurs when the spring is at maximum displacement, so at
x = A
where A is the amplitude of the motion.
The maximum displacement is given by Hook's law:
where
F is the force applied initially to the spring, so it is equal to the weight of the block:
k = 160 N/m is the spring constant
Solving for A, we find
Answer:
I believe it is a transfer of energy from the rubber band to the car
Explanation:
However it could be a transfer of potential energy from the stretched rubber band that is released into kinetic energy into the car. Depends as there is little context to the question.
