# Answer to Question #12975 in Mechanics | Relativity for Sara

Question #12975

A car of mass 1100 Kg drives with a velocity such that it has a kinetic energy of 400 kJ ( see the Figure). Find the velocity. If the car is raised with a carne how high should it be lifted in the standard gravitational field (9.81 m/s2) to have a potential energy that equals the kinetic energy?

Expert's answer

(i)

KE = m * V^2 / 2

V = sqrt(2 * KE / m)

V = sqrt(2 * 400000 / 1100) =

26.968 m/s

(ii)

PE = m * g * h. If PE = KE,

h = KE / (m * g)

h =

400000 / (1100 * 9.81) = 37.068 m

KE = m * V^2 / 2

V = sqrt(2 * KE / m)

V = sqrt(2 * 400000 / 1100) =

26.968 m/s

(ii)

PE = m * g * h. If PE = KE,

h = KE / (m * g)

h =

400000 / (1100 * 9.81) = 37.068 m

## Comments

Assignment Expert23.06.16, 15:56Dear lateifa, please use panel for submitting new questions.

lateifa22.06.16, 11:28Question 6:

A 100 kg roller coaster is released from position "A" with an initial speed of 30 m/s. The designer of the roller coaster wants the cart to come to a complete stop at point "B". How high must point "B" be above the ground? (use g = 9.8 m/s2)

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