Question

1. is it possible that a force changes only the direction of motion without changing the speed of object. explain with the help of example.

2. A blacksmith hammers a hot piece of iron while making a tool. how does the force due to hammering affect the piece of iron?

Answer 1

1) a body rotating, it  is constantly changing its direction due to the outward and inward force. But still the speed is constant. we can take the example of earth or any other planets. it is moving continuously in a elliptical path. The forces are changing its direction. But the speed is not changed. Even the fan on the ceiling  it keeps on rotating changing its direction bt the speed is constant unless we change it. 
2) when the substances are hot they can easily be adjusted to a different shape. When the substances are heated their molecules get energy and this will make them to change their state from their equilibrium. in this condition, when we apply a force , the molecules will alter their shape according to the force. 
when we hammer the hot piece of iron , actually we are applying a force over the iron. This force will change the molecules in the direction of the force applied. Thus we can adjust the shape of iron