Answer:
150000000000 m
0.0000005 seconds
33.33 ns
Explanation:
Speed of electromagnetic waves through vacuum = 
Echo time = 1000 seconds
Echo time is the time taken to reach the object and come back to the observer
Distance = Speed×Time

Venus is 150000000000 m away from Earth
Time = Distance / Speed

Echo time will be twice the time

The echo time will be 0.0000005 seconds
Difference in time = Difference in distance / Speed

The accuracy by which I will be able to measure the echo time is 33.33 ns
Answer:
The Celcius and kelvin scale are related unit for unit. One degree unit on the Celcius scale is equivalent to one degree unit on the kelvin scale. The only difference between these two scales is the zero point.
An LED is useful because when a current passes through it, it gives out light.
Answer:
heat energy and nuclear energy
Explanation:
as a resukt of nuclear fusion, the sun produces two types of energy.
1. heat energy
2. nuclear energy
In order from shortest to longest frequency, the electromagnetic waves can be ranked :
1. X-rays
2. Ultraviolet
3. Infrared
4. Microwave
X-rays has the shortest frequency which ranges between 30 petahertz to 30 exahertz. X-rays have the smallest wavelengths at 0.01-10 nanometers. Its energy ranges between 100eV to 100keV.