Content

Key opportunities for skills development

Students should be able to calculate the amount of energy associated with a moving object, a stretched spring and an object raised above ground level.

WS 1.2, 4.3, 4.4, 4.6

MS 1a, c, 3b, c

The kinetic energy of a moving object can be calculated using the equation:

$k i n e t i c e n e r g y = 0.5 \times m a s s \times (s p e e d)^{2}$

$[E_{k} = \frac{1}{2} m v^{2}]$

kinetic energy,E_k, in joules, J

mass,m, in kilograms, kg

speed,v, in metres per second, m/s

The amount of elastic potential energy stored in a stretched spring can be calculated using the equation:

MS 3b, c

Students should be able to recall and apply this equation.

$e l a s t i c p o t e n t i a l e n e r g y = 0.5 \times s p r i n g c o n s t a n t \times (e x t e n s i o n)^{2}$

${[E}_{e} = \frac{1}{2} k e^{2}]$

(assuming the limit of proportionality has not been exceeded)

elastic potential energy,E_e, in joules, J

spring constant,k, in newtons per metre, N/m

extension,e, in metres, m

The amount of gravitational potential energy gained by an object raised above ground level can be calculated using the equation:

MS 3b, c

Students should be able to apply this equation which is given on thePhysics equation sheet.

$g . p . e . = m a s s \times g r a v i t a t i o n a l f i e l d s t r e n g t h \times h e i g h t$

$[E_{p} = m g h]$

gravitational potential energy,E_p, in joules, J

mass,m, in kilograms, kg

gravitational field strength,g, in newtons per kilogram, N/kg (In any calculation the value of the gravitational field strength (g) will be given).

height,h, in metres, m

MS 3b, c

Students should be able to recallandapply this equation.

AT 1

Investigate the transfer of energy from a gravitational potential energy store to a kinetic energy store.