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A spherical object of mass 150kg is orbiting the Earth. The distance between the centre of the object and the centre of the Earth is 25,000m. What is the kinetic energy of the object?

This is an example of circular motion caused by a centripetal force. In this case, the centripetal force is the gravitational force between the Earth and the object. Linking the equations for circular ...

Answered by Ryan L. Physics tutor
2419 Views

Explain how fluorescent tubes work

Fluorescent tubes are filled with low pressure mercury, when an electric current is passed through, the electrons in mercury are excited and move to a high energy level, this high level state is unstab...

Answered by Michael W. Physics tutor
26943 Views

A ball of mass 0.7 kg strikes the wall at an angle of 90 degrees with speed 72 km/h. Consider that the bounce lasts for 0.1 s and is perfectly elastic. What is the magnitude of the average reaction force from the wall that acts on the ball?

initial speed: v =  72 km/h = 20 m/s. 
mass: m = 0.7 kg
time of the impact: t = 0.1 s
average force: F
The speed after impact is the same as initial speed, but velocity has got ...

Answered by Filip M. Physics tutor
3741 Views

What is the difference between speed and velocity?

Speed and velocity may seem like identical measures but this is not the case. Speed is a scalar measurement meaning it only takes into account magnitude not direction, velocity is a vector quantity and...

Answered by Alexander A. Physics tutor
6177 Views

Resolving the forces for an object suspended on two strings.

Imagine a following situation: a stationary (not moving) object with a mass of 5 kg is suspended in the air by two strings. The angles between strings and the vertical directions are 15 and 55 degrees. Wh...

Answered by Filip W. Physics tutor
17041 Views

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