Forces are responsible for changing the motion of objects. If more than one force is present, the shape of an object can also be changed.
How might the shape of an object change if forces act away from each other in a straight line?
It might extend
It might compress
It might bend
Which word describes an object that will return to its original shape when forces are removed?
What is another name for the limit of proportionality?
What is the unit for the spring constant?
Newtons per metre squared (N/m2)
Newtons per metre (N/m)
What is the name for energy stored by a stretched spring?
Elastic potential energy
Gravitational potential energy
Which equation gives the energy stored by a stretched spring?
E = k x
E = ½ k2 x
E = ½ k x2
A spring has a spring constant of 120 N/m. It is stretched from 30 cm to 50 cm. What would the elastic potential energy stored by the spring be?
0.5 x 120 × (0.3)2 = 5.4 J
0.5 x 120 × (0.5)2 = 15.0 J
0.5 x 120 × (0.2)2 = 2.4 J
A spring extends elastically by 10 cm when a force of 20 N is applied to it. What force would be needed to extend the spring by 5 cm?
How is work done calculated?
Work done = force × distance
Work done = distance ÷ force
Work done = force ÷ distance travelled
How much work is done when a ball is moved 1.5 m by a force of 12 N?