Answer the following question given this paragraph: 

Figure 10.18 The first image shows how helicopters store large amounts of rotational kinetic energy in their blades. This energy must be put into the blades before takeoff and maintained until the end of the flight. The engines do not have enough power to simultaneously provide lift and put significant rotational energy into the blades. The second image shows a helicopter from the Auckland Westpac Rescue Helicopter Service. Over 50,000 lives have been saved since its operations beginning in 1973. Here, a water rescue operation is shown. (credit: 111 Emergency, Flickr).


Q: Helicopters store large amounts of rotational energy of what type in their blades?

 Choices:

- magnetic

- seismic

- thermal

- kinetic

A:
kinetic
