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A 0.20 kg mass is whirled round in a vertical circle on the end of a light string of length 0.90 m. At the top point of the circle the speed of the mass is 8.2 m/s. What is the tension in the string at this point?

A diagram would be very beneficial for this problem. We can draw a free body force diagram of the mass. At the top of the circle the two forces acting on it are its weight and tension from the string. Bot...

Answered by Thomas C. • Physics tutor

48529 Views

If a cricket ball of mass 500g is thrown upwards from the ground with an initial velocity of 20 m/s, how high will the ball reach?

The best method of answering this question would be to look at the energy of the ball at the moment it is thrown and at the moment it reaches its highest point.
When the ball is thrown, initially all...

Answered by Thomas C. • Physics tutor

11806 Views

What is an (electrostatically) induced charge?

When an electrically charged object (e.g rod) charges an uncharged object (e.g. metal sphere) that is nearby with the opposite charge.

How does this happen?

Answered by Herminia T. • Physics tutor

20890 Views

Two electrons are a distance r apart, the first electron exerts a force F on the second electron. a) What force does the second electron exert on the first? b) In terms of r, at what distance is the force that the first electron exerts on the second F/9?

This question is on electric forces between charged particles. A useful equation to consider is Coulomb's law:F=k(Q₁Q₂

Answered by Ross W. • Physics tutor

6191 Views

A rollercoaster carriage of mass 100kg has 45kJ of Kinetic Energy at the lowest point of its ride. Ignoring air resistance and friction between the wheels and the tracks, what is the maximum height above this point it could reach? [Take g as 10m/s/s)

[A useful tip: always start by drawing a diagram!!]This question is asking you to apply conservation of energy, i.e. at the highest point it can reach above the lowest point, all of this Kinetic Energy wi...

Answered by Ross W. • Physics tutor

3601 Views