ten bricks each 6.0cm thick and mass of 1.5kg, lie on a table, how much work is required to stack them one on the top of another?
A. 40j
B. 88j
C. 45j
D. 0j
E. None of these
Well, stacking bricks can be quite tiring. But let me do the math for you.
To stack the bricks, we need to calculate the work done in lifting each brick to the top. The work done is equal to the force applied multiplied by the distance moved in the direction of the force.
The force required to lift a brick is equal to its mass multiplied by the acceleration due to gravity, which is approximately 9.8 m/s².
The distance moved in the direction of the force is equal to the thickness of one brick, which is 6.0 cm or 0.06 m.
So, the work done in lifting one brick is:
Work = Force x Distance
W = m x g x d
W = 1.5 kg x 9.8 m/s² x 0.06 m
Calculating that, we get:
W = 0.882 J
Since we have ten bricks, we multiply this work by 10:
Total Work = Number of bricks x Work done on each brick
Total Work = 10 x 0.882 J
Total Work = 8.82 J
Therefore, the correct answer is B. 88 J.
To calculate the work required to stack the bricks, we need to determine the height of the stack. Since each brick is 6.0cm thick, the total height of the stack will be 6.0cm multiplied by the number of bricks.
Given that there are ten bricks, the total height of the stack is:
Height = 6.0cm/brick * 10 bricks = 60.0cm
To calculate the work, we will use the formula:
Work = Force * Distance
The force required to lift each brick is equal to its mass multiplied by the acceleration due to gravity (w = m * g). The distance is equal to the height of the stack. Since the bricks are already on the table, there is no need to lift them against gravity, and therefore no work is required. Hence, the answer is:
D. 0j
To determine the amount of work required to stack the bricks on top of each other, we need to calculate the total gravitational potential energy gained in the process.
The formula for gravitational potential energy is given by:
Potential Energy = mass × gravity × height
In this case, the height refers to the distance that each brick is raised when it is stacked on top of the previous one. Since the height remains constant (as the thickness of each brick is given as 6.0 cm), we can simplify the calculation by considering the total height as the product of the height of each brick (6.0 cm) and the number of bricks stacked.
The total mass of all the bricks can be calculated by multiplying the mass of a single brick (1.5 kg) by the number of bricks (10).
So, the total work done is:
Work = Potential Energy = (mass of 10 bricks) × gravity × (height of each brick) = (1.5 kg × 10) × 9.8 m/s² × (6.0 cm)
To convert the height from centimeters to meters, we divide it by 100:
Work = (1.5 kg × 10) × 9.8 m/s² × (6.0 cm / 100 cm/m) = (1.5 kg × 10) × 9.8 m/s² × 0.06 m
Simplifying further:
Work = (15 kg) × (9.8 m/s²) × (0.06 m) = 8.82 kg·m²/s² or 8.82 joules (J)
Therefore, the answer is B. 88J.
original height of center of mass = 3 cm
final height of center of mass = 5^6 = 30cm
change in height of GC = 30-3 = 27 cm=.27m
work = m g h = 15 * 9.8 * .27 = 39.69 or 40 J so A