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
<span>Scientists follow a set order of steps when carrying out a scientific investigation to make sure that the method, interpretation and results that they have obtained are repeatable and reliable. This kind of information can be truly said that their data is true and valid. </span>
the greater the <u>mass</u> of an object the more force is needed to cause acceleration
1 and A
2 and B
3 and D
4 and C