Answer:
The tension is
Explanation:
From the question we are told that
The total mass is
The radius is
The density of air is
Generally the upward force acting on the balloon is mathematically represented as
=>
=>
Here V is the volume of the spherical helium filled balloon which is mathematically represented as
=>
=>
So
Answer:A
Explanation:
In R-L circuit current is given by
where i=current at any time t
R=resistance
L=Inductance
at t=0 approaches to 1
therefore
i=0
when t approaches to ,
approaches to zero
thus
thus we can say that initially circuit act as broken wire with zero current
and it increases exponentially with time and act as ordinary connecting wire
Answer:
39.81 N
Explanation:
I attached an image of the free body diagrams I drew of crate #1 and #2.
Using these diagram, we can set up a system of equations for the sum of forces in the x and y direction.
∑Fₓ = maₓ
∑Fᵧ = maᵧ
Let's start with the free body diagram for crate #2. Let's set the positive direction on top and the negative direction on the bottom. We can see that the forces acting on crate #2 are in the y-direction, so let's use Newton's 2nd Law to write this equation:
Note that the tension and acceleration are constant throughout the system since the string has a negligible mass. Therefore, we don't really need to write the subscripts under T and a, but I am doing so just so there is no confusion.
Let's solve for T in the equation...
We'll come back to this equation later. Now let's go to the free body diagram for crate #1.
We want to solve for the forces in the x-direction now. Let's set the leftwards direction to be positive and the rightwards direction to be negative.
The normal force is equal to the x-component of the force of gravity.
Now let's go back to this equation:
We have 3 known variables and we can solve for the tension force.
The tension force is the same throughout the string, therefore, the tension in the string connecting M2 and M3 is 39.81 N.
