Answer:
3500j
0.250 kg
14.14 m/s
220500 j
93.91 m/s
Explanation:
K.E =1/2 m v^2
first question
1/2×700×10=3500 j
second question
2×78.2/25^2= 0.250 kg
Third question
8kj=8000j
root (2×8000/80)= 14.14 m/s
Last one
P.E=MGH
so it will be
P.E=50×450×9.8=220500 j
the speed
root (2×220500/50)=93.91 m/s