Answer:
20 J
Explanation:
Kinetic energy is given as half of the product of mass and the square of velocity of an object:
KE = 
where m = mass = 40 kg
v = velocity = 1 m/s
Hence, Mary's kinetic energy is:
KE = 
KE = 20 * 1 = 20 J
She has a kinetic energy of 20 J.
Answer:
To decide where the balls land, we need to determine how long the balls are in the air. Both balls will take 2 seconds to hit the ground.
Explanation:
1) Time played forward : gravity & drag forces are in opposite directions so it takes a longer time to reach the ground. 2) Time played backward : gravity & drag forces are in the same direction so it takes a shorter time to reach the ground.
For electrical devices . . .
Power dissipated = (voltage) x (current) =
(12 V) x (3.0 A) = 36 watts .
1 watt means 1 joule per second
(36 joule/sec) x (60 sec/min) x (10 min) = 21,600 joules
They have similar physical and chemical properties because of thier valence electrons
The answer is attract. Hope it helps! :)