50.0k views
1 vote
A bobsleigh with four people on board has a total mass of 610 kg. How fast is the sleigh moving if it has a kinetic energy of 40.0 kJ?

User Mishal
by
6.7k points

2 Answers

4 votes
40 kj to j is 40000 j, we know that KE=(1/2)mv², therefore v=√2K/m, therefore v=√2×40000j/610kg, v=11.5 m/s
User Nurettin
by
6.0k points
5 votes

Answer:

v= 11.45
(m)/(s)

Step-by-step explanation:

kinetic equation


E_(k) = (1)/(2) * m * v^(2),
E_(k) = 40.0 k J ,
m=610 kg


E_(k)*2 = m * v^(2)\\(2*E_(k))/(m) = v^(2) \\v =  \sqrt{(2*E_(k))/(m) } \\v =  \sqrt{(2*40x10^(3) (kg*m^(2) )/(s^(2))  )/(610 kg) } = \sqrt{131.147 (m^(2))/(s^(2)) } \\


v= 11.45 (m)/(s)

User Bodine
by
6.7k points