John runs for 10 mins at a uniform speed 9kn/h. at what speed should he run for the next 20mins so that theaverage speed comes to 12km/h.

13.5 km/h

Explanation:

John runs for 10 min at 9 km/h, then 20 min at v.  He will have run a total of 30 min at 12 km/h.

Therefore:

(30 min) (12 km/h) = (10 min) (9 km/h) + (20 min) v

v = 13.5 km/h

the simple machine has three main features. they are:

fulcrum is the center point or pivot point of the machine. effort is input force/ applied force. load is external force/ output.

the keisha 's machine labels are

x : load

y: fulcrum

z: lever