Efficiency = (energy that does the job) / (total energy used)
= (45 J) / (120J)
I think you can handle the division.
Velocity = 14 m/s
Time = 20 s
Displacement = Velocity×Time = (14×20) m = 280 m
The displacement is 280 m towards the direction of motion.
Answer:
221754385964.9123
Explanation:
Convert miles to nanometer
1 mile = 1.6 km
1 km = 1×10³×10³×10³×10³ nm
1 mile = 1.6×10¹² nm
So,
158 miles = 158×1.6×10¹² = 252.8×10¹² nm
Length of each molecule = 1140 nm
Number of molecules = Total length / Length of each molecule

There are 221754385964.9123 number of molecules in a stretch of 158 miles
Answer:
1.) Current = 213.33A
2.) Potential difference = 3200 V
Explanation:
Given that
Number of electrons n = 4 x 10^21 electrons
Resistance R = 15 ohm
Time t = 3 s
From the definition of current ;
Current is the rate of flow of changes. That is,
Current I = Q/t
Where
Q = 4 × 10^21 × 1.6 × 10^-19
Q = 460C
Current I = 460/3
Current I = 213.33 A
Using Ohms law which state that
V = IR
Substitute the resistance R and current I into the formula above
Potential difference V = 213.3 × 15
Potential difference V = 3200 V