Electromagnetic waves do not require a medium to travel through. They can travel through empty space or matter.
        
             
        
        
        
Wavelength = (speed) / (frequency) = (460 m/s) / (230/sec) = <em>2 meters</em>
        
             
        
        
        
This would be a cryogenic intermodal tank. These are used to store and transport HAZMAT gases that require storage under specific pressure and temperature parameters. Cryogenic Intermodal tanks have pressure of 25 Psi or less. 
        
             
        
        
        
1. Humidity cannot be used to predict rain. 
2. I'm pretty sure it's weather but I'm not 100% sure. Maybe like 89% sure.
3. Tempurature doesn't affect humidity.
4. Not sure but I think its the 3rd one
        
             
        
        
        
The car should have a velocity of 60 m/s to attain the same momentum as that of the truck of 2000 kg.
Answer:
Explanation:
Momentum is measured as the product of mass of object with the velocity attained by that object. 
Momentum of 2000 kg truck = Mass × Velocity
Momentum of 2000 kg truck = 2000×30 = 60000 N
Similarly, the momentum of 1000 kg car will be 1000× velocity of the 1000 kg car.
Since, it is stated that momentum of 2000 kg truck is equal to the momentum of 1000 kg of car, then the velocity of 1000 kg of car can be determined by equating the momentum of car and truck.
Momentum of 2000 kg truck = Momentum of 1000 kg car
60000=1000×velocity of 1000 kg car
Velocity of 1000 kg car = 60000/1000=60 m/s
So, the car should have a velocity of 60 m/s to attain the same momentum as that of the truck of 2000 kg.