A pump jack scaffold must be fitted with two positive gripping mechanisms to prevent slippage. Pump jacks are a uniquely designed scaffold consisting of a platform supported by movable brackets on vertical poles. The brackets are designed to be raised and lowered in a manner similar to an automobile jack. It is important to make sure that pump jack brackets have two positive gripping mechanisms to prevent any failure or slippage.
When you rub a balloon on a sweater, for example, some electrons come off and end up on the balloon. The fibers have lost electrons giving them a positive charge. The rubber gained electrons giving it a negative charge. ... The positively charged fibers are now attracted to the negatively charged balloon.
B) law of conservation of momentum
It states that the total momentum of a system before impact is the same as the total momentum of the system after impact.
In this case total momentum before impact:
10kg*5m/s + 5kg * 0m/s = 50 kg m/s
After Impact:
10kg*0m/s + 5kg*10m/s = 50 kg m/s
You can see the momentum before and after impact is same as 50 kg m/s
Of course we assumed that the first cart stopped after the impact, and there are no energy losses.
Resistance-1 = (voltage-1) / (current-1) =
(12 V) / (0.185 A) = 64.9 ohms .
Resistance-2 = (voltage-2) / (current-2) =
(90 V ) / (1.25 A) = 72 ohms .
The resistance changed between situation-1 and situation-2 .
How did that happen ?
Power = (voltage) x (current)
Power-1 = (12) x (0.185) = 2.22 watts
Power-2 = (90) x (1.25) = 112.5 watts
The poor resistor dissipated 51 times as much power during
the second trial. It got all heated up, and its resistance went
through the roof.
Carbon resistors behave nicely and reliably, until you try to
toast bread or light up your bedroom with them.
