heat released Q = 749 joules
heat of fusion of silver L = 109 J/g
Here phase of silver is changing from liquid to solid
so temperature will remain same
all heat will be released due to its phase change
and in this case we use Q=mL
where m is the mass of silver in gram
Q= mL
749 = m * 109
m = 749/109
m = 6.87 gram
Yes!
I think there are two ways you could go with this answer:
1) Acceleration is the change in velocity over time, it can be negative or positive. If you have an object that is already moving forwards in a straight line and give it a constant negative acceleration, it will slow down and then start going in reverse.
2)Velocity is a vector, meaning it has both magnitude and direction. In the example above, the acceleration is due to a change in magnitude, or speed (from +ve to -ve) but not a change in direction. Something that has constant speed but is changing direction is also accelerating (like something that is orbiting). You could use the earth as an example, which is constantly accelerating due to moving in a circle around the sun. At any time in the year you can say that in half a year's time the earth's direction will be reversed.
To solve this problem it is necessary to apply the kinematic equations of angular motion.
Torque from the rotational movement is defined as
where
I = Moment of inertia 
For a disk
Angular acceleration
The angular acceleration at the same time can be defined as function of angular velocity and angular displacement (Without considering time) through the expression:
Where
Final and Initial Angular velocity
Angular acceleration
Angular displacement
Our values are given as
Using the expression of angular acceleration we can find the to then find the torque, that is,
With the expression of the acceleration found it is now necessary to replace it on the torque equation and the respective moment of inertia for the disk, so
Therefore the torque exerted on it is 
Answer:
y = 52.44 10⁻⁶ m
Explanation:
It is Rayleigh's principle that two points are resolved if the maximum of the diffraction pattern of one matches the minimum the diffraction pattern of the other
Based on this principle we must find the angle of the first minimum of the diffraction expression
a sin θ= m λ
The first minimum occurs for m = 1
sin θ = λ / a
Now let's use trigonometry the object is a distance L = 0.205 m
tan θ = y / L
Since the angles are very small, let's approximate
tan θ = sin θ/cos θ = sin θ
sin θ = y / L
We substitute in the diffraction equation
y / L = λ / a
y = λ L / a
Let's calculate
y = 550 10⁻⁹ 0.205 / 2.15 10⁻³
y = 52.44 10⁻⁶ m
