Answer:
3 m/s
Explanation:
Average Speed = 
Plug in the numbers, it will be (6m + 3m) divided by (2s + 1s), which is 9m/3s, which equals to 3m/s.
The relationship between the distance covered, initial and final speeds, and time can be expressed through the equation,
First equation,
2ad = Vf² - Vi²
Substituting the known values,
2(a)(0.230 km) = (70 km/h)² - (40 km/h)²
The value of a from the equation is 7173.92 km/h².
Second equation,
d = (Vi)(t) + 0.5at²
Substituting the known values,
0.230 km = (40 km/h)(t) + (0.5)(7173.92 km/h²)(t²)
The value of t from the equation is 4.1818 x 10^-3 hours which is also equal to 0.2509 minutes or 15 seconds.
Answer: 15 seconds
Atomic number=Proton count
Atomic mass=Proton count+ neutron count
Neuton Count=Atomic mass-Proton count
Proton count=Atomic number=27
Mass number=74
Neuton count= 74-27=47
Answer:
His machine must increase
Explanation:
You could use the formula
W=Fd
F(force)=20N
D(distance/displacement) =15m
W=(20N)(15m)
W= 300 J