First of all, this is the chemistry section, while your question is a physics question. Anyway I'll tell you how to solve it.
First we need to find the rate that the truck moves in a second.
1km = 1000m
40km = 40000m
40000m/hr
1 hour = 60 minutes
40000m/hr ÷ 60 = 666.66(repeating)/minute
1 minute = 60 seconds
666.66m/min ÷ 60 = 11.11(rep)m/s
Next we simply multiply the speed of the truck by the number of seconds it travels.
11.11 × 5 = 55.55
Make sure to round it unless you indicate the repeating decimal.
The truck moved 55.56m in 5 seconds.
When hydrochloric acid and zinc were combined, the salt zinc chloride and hydroge gas are being produced in the flask. The flask was said to be sealed and, therefore, no gas could escape from the flask. As the temperature decreases, the pressure inside would decrease since the gas would have lower kinetic energy and would have less force to exert on the walls of the flask. This is also evident from the equation PV = nRT. As we can see pressure and temperature are directly related which means as one decreases, the other decreases as well or as one increases, the other would increase accordingly.
It's the form of energy in a moving object or a particle. It is present in any object that has a mass and a speed.
Kinetic energy = 1/2 mv²
