1) A The 78g
2) C Push on the wagon in the opposite direction as Jack with a force that is the same as Jack is applying.
Answer: 40
Explanation:
= 34 + 5 * 1.2465
= 40.2325
= 40
The number of significant figures in the answer should be the same as the number with the least number of significant figures that any of the digits in the equation have.
32 has 2 significant figures so the answer has to be 2 significant figures which is 40.
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
Put oil on a table, that would reduce friction