Question

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

Answer 1

Answer:

1.4 m/s

Explanation:

The velocity can be found by using the formula

$v = \sqrt{ \frac{2k}{m} }$

k is the kinetic energy

m is the mass

From the question we have

$v = \sqrt{ \frac{2 \times 4116}{4200} } \\ = 1.4$

We have the final answer as

1.4 m/s

Hope this helps you

Answer 2

Answer:

The speed of the lift is 1.4 m/s

Explanation:

Kinetic Energy

Is the type of energy of an object due to its motion. It's proportional to the square of the speed and the mass.

The equation for the kinetic energy is:

$\displaystyle K=\frac{1}{2}mv^2$

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

It's given the mass of the lift as m=4,200 kg and its kinetic energy K=4,116 J. To calculate the speed (magnitude of velocity), we solve the formula for v as follows:

$\displaystyle v=\sqrt{\frac{2k}{m}}$

$\displaystyle v=\sqrt{\frac{2*4,116}{4,200}}$

$\displaystyle v=\sqrt{1.96}$

v = 1.4 m/s

The speed of the lift is 1.4 m/s