Kinetic energy = (1/2) (mass) x (speed)²
At 7.5 m/s, the object's KE is (1/2) (7.5) (7.5)² = 210.9375 joules
At 11.5 m/s, the object's KE is (1/2) (7.5) (11.5)² = 495.9375 joules
The additional energy needed to speed the object up from 7.5 m/s
to 11.5 m/s is (495.9375 - 210.9375) = <em>285 joules</em>.
That energy has to come from somewhere. Without friction, that's exactly
the amount of work that must be done to the object in order to raise its
speed by that much.
Answer:
Simple machine: pair of tongs, seesaw and wheelbarrow
Compound machine: sewing machine, fishing rod and reel and crane.
Explanation:
Simple machine is the simplest device to use mechanical advantages. It has simplest mechanism to multiply the magnitude of force.
So, pair of tongs, seesaw and wheelbarrow are the example of simple machine because their mechanism is simplest.
Compound machine is a device that is made up of more than one simple machine.
so, sewing machine, fishing rod and reel and crane are example of compound machine because these devices shows more than one machine in it.
Thus, classification is as follows:
Simple machine: pair of tongs, seesaw and wheelbarrow
Compound machine: sewing machine, fishing rod and reel and crane.
Answer:
a = 9.8 m/s²
Explanation:
Acceleration due to gravity on Earth is constant, which is 9.8 m/s²
