208,650 views
25 votes
25 votes
A lift travelling up to the top floor of the Empire State building with a mass of 4200kg and a kinetic energy of 4116J. find the velocity

please helpp

User Eduardo Ortiz
by
2.8k points

1 Answer

22 votes
22 votes

Answer:


v = 1.4 m/s

(v= velocity)

Step-by-step explanation:

Kinetic Energy is computed using the formula


KE = (1)/(2)mv^2

where m = mass of the object in kg and v is the velocity in m/s

Given KE = 4116J,
m = 4200 kg

Substitute and solve for v


4116 = (1)/(2)4200\cdot v^2

=>
4116 = 2100\cdot v^2


v^2 = (4116)/(2100)\\\\v^2 = 1.96\\\\v = √(1.96)\\\\v = 1.4 m/s

User Humble Learner
by
3.0k points