Final answer:
The refrigeration unit should be supported by five equal springs to ensure that 15 percent or less of the unbalance is transmitted to the foundation.
The Correct Option is; C) Six springs
Step-by-step explanation:
In order to determine the number of springs needed to support the refrigeration unit, we need to consider the level of unbalance transmitted to the foundation.
The question states that 15 percent or less of the unbalance should be transmitted to the foundation. Therefore, we need to find the minimum number of springs that satisfies this condition.
If the unit is supported by six equal springs, each spring will bear an equal share of the weight. So, the spring constant for each spring can be determined by dividing the total weight of the unit by the number of springs. If the total weight of the unit is 30 kg, then each spring will need to support 5 kg.
Now, considering that the springs are equal, and 15 percent or less of the unbalance should be transmitted to the foundation, we can determine the minimum number of springs needed as follows:
Assuming x number of springs, the maximum weight that a single spring should bear is 5 kg + (15/100 * 5 kg) = 5.75 kg.
- If we assume 4 springs, then each spring will have to bear 30 kg/4 = 7.5 kg, which is above the maximum weight of 5.75 kg.
- If we assume 5 springs, then each spring will have to bear 30 kg/5 = 6 kg, which is within the maximum weight limit.
- If we assume 6 springs, then each spring will have to bear 30 kg/6 = 5 kg, which is within the maximum weight limit.
- If we assume 7 springs, then each spring will have to bear 30 kg/7 = 4.2857 kg, which is within the maximum weight limit.
Therefore, the answer is B) Five springs, as it satisfies the condition of 15 percent or less of the unbalance being transmitted to the foundation.