7. Zena has a model plane attached to a rod as shown below.
The plane is balanced by a sliding counterweight.
sliding
counterweight
10 cm
20 cm
rod
pivot
5 N
not to scale
St George's Catholic School
Page
(a) The rod is balanced horizontally.
Calculate the turning moment produced by the counterweight about the
pivot.
Give the unit.
KANNN
2 mark​

You have been hired to design a spring-launched roller coaster thatwill carry two passengers per car. the car goes up a 10-m highhill, then descends 15m to the track's lowest point. you'vedetermined that the spring can be compressed a maximum o 2.0m andthat a loaded car will have a maximum mass of 400kg. for safetyreasons, the spring constant should be 10% larger than the minimumneeded for the car to just make it over the top. a) what spring constant (k) should you specify ? b) what is the maximum speed of a 350 kg car if the spring iscompressed the full amount.