The 100 kg block in figure takes 7.00s to reach the floor after being released from rest. What is the mass of the block on the left?

Unfortunately, I cannot see the figure you are referring to, so I am unable to provide a specific answer. However, I can help guide you through the steps to find the mass of the block on the left.

To find the mass of the block on the left, we need to use the concept of conservation of energy. When the block on the left falls, its potential energy is converted to kinetic energy as it accelerates towards the ground.

The formula to calculate potential energy is given by:
Potential Energy = mgh
Where:
m = mass of the object (block on the left)
g = acceleration due to gravity (approximately 9.8 m/s^2)
h = height from which the object is released

To calculate the potential energy of the block on the left, we need to know the height from which it is released.

Once we have determined the potential energy, we can equate it to the kinetic energy of the block on the right, which is given by:
Kinetic Energy = 0.5 * m * v^2
Where:
m = mass of the object (block on the right)
v = velocity of the object when it reaches the floor

We can rearrange the equation to solve for the mass of the block on the right:
m = 2 * (Potential Energy / v^2)

Using the given information, once you have the height from which the block is released, you can substitute the values into the equations to find the masses of the two blocks.

To find the mass of the block on the left, we can make use of the concept of conservation of energy.

First, let's analyze the situation:
- The 100 kg block falls freely and reaches the floor in 7.00 seconds.
- We need to find the mass of the block on the left.

Now, let's discuss the steps to find the solution:

Step 1: Determine the height of the block on the left.
- To do this, we need to calculate the distance traveled by the falling block.
- We can use the formula for the distance traveled during free fall:
distance = 1/2 * acceleration due to gravity * time^2
- In this case, the time is 7.00 seconds, and the acceleration due to gravity is approximately 9.8 m/s^2.

Step 2: Calculate the potential energy of the falling block.
- The potential energy can be calculated using the formula:
potential energy = mass * acceleration due to gravity * height
- In this case, the mass is 100 kg, the acceleration due to gravity is 9.8 m/s^2, and the height is the distance traveled calculated in Step 1.

Step 3: Calculate the potential energy of the block on the left.
- We can assume that the block on the left is at the same height as the falling block when it starts.
- Therefore, the potential energy of the block on the left can be calculated using the formula:
potential energy = mass of the block on the left * acceleration due to gravity * height
- In this case, we need to solve for the mass of the block on the left.

Step 4: Equate the potential energy of the falling block and the block on the left.
- Since energy is conserved, we can equate the potential energies calculated in Steps 2 and 3:
mass * acceleration due to gravity * height = mass of the block on the left * acceleration due to gravity * height
- We can cancel out the height and acceleration due to gravity terms from both sides of the equation.

Step 5: Solve for the mass of the block on the left.
- By rearranging the equation obtained in Step 4, we can solve for the mass of the block on the left:
mass of the block on the left = mass of the falling block * (time taken to reach the floor / time taken to reach the left block)
- In this case, the mass of the falling block is 100 kg and the time taken to reach the floor is 7.00 seconds.

By following these steps and performing the necessary calculations, you will find the mass of the block on the left.

No figure was provided. It sounds like an "Atwood machine" problem, with two masses connected by a pulley.

The acceleration of such a device is
a = g*(M1-M2)/(M1+M2) if friction and pulley mass can be ignored.

See http://hyperphysics.phy-astr.gsu.edu/hbase/Atwd.html
for more about this kind of problem