Question 1
Fig. 2.1 shows solar-powered traffic warning lights.
Fig. 2.1
The energy from the solar cell is stored in a battery.
Name the energy store in the battery.
Fig. 2.1 shows solar-powered traffic warning lights.
Fig. 2.1
The energy from the solar cell is stored in a battery.
Name the energy store in the battery.
chemical (energy store)
A student drops a heavy ball from a vertical height of 1.8 m above the ground. The ball then falls to the ground. It does not bounce after hitting the ground.
Describe the transfers of energy of the ball between stores from when the ball begins to fall to when it reaches the ground.
gravitational (potential) energy (store before/ as the ball falls)
kinetic energy (store) increases (as the ball falls) OR energy transferred to kinetic energy (store as the ball falls)
(energy transferred from) kinetic energy (store) to internal / thermal energy (store)
A girl holds a rubber ball out of a window of a tall building. The mass of the ball is 0.20 kg . The ball is at rest 10 m above a concrete path.
Calculate the gravitational potential energy of the ball relative to the concrete path.
20 J
(Δ.Ep=)mg(Δ)h OR 0.2(0)×9.8×10
The girl releases the ball and it falls towards the path. The ball strikes the path and bounces vertically upwards.
Fig. 1.1 shows the ball falling towards the path.
Fig. 1.1
The speed of the ball immediately before it strikes the path is 14 m/s.
The speed of the ball immediately after it strikes the path is 12 m/s.
Calculate the kinetic energy of the ball immediately after it strikes the concrete path.
14 J
(Ek=)21mv2OR21×0.2(0)×122