As long as it sits on the shelf, its potential energy
relative to the floor is . . .
Potential energy = (mass) x (gravity) x (height) =
(3 kg) x (9.8 m/s²) x (0.8m) = <u>23.52 joules</u> .
If it falls from the shelf and lands on the floor, then it has exactly that
same amount of energy when it hits the floor, only now the 23.52 joules
has changed to kinetic energy.
Kinetic energy = (1/2) x (mass) x (speed)²
23.52 joules = (1/2) x (3 kg) x (speed)²
Divide each side by 1.5 kg : 23.52 m²/s² = speed²
Take the square root of each side: speed = √(23.52 m²/s²) = <em>4.85 m/s </em> (rounded)
Answer:
360 N
Explanation:
m = 30kg u = 2 m/s a = -2m/s/s
Since the object has an initial velocity of 2 m/s and acceleration of -2 m/s/s
the object will come to rest in 1 second but the force applied in that one second can be calculated by:
F = ma
F = 30 * -2
F = -60 N (the negative sign tells us that the force is acting downwards)
Now, calculating the force applied on the box due to gravity
letting g = -10m/s/s
F = ma
F = 30 * -10
F = -300 N (the negative sign tells us that the force is acting downwards)
Now, calculating the total downward force:
-300 + (-60) = -360 N
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<em>Hence, a downward force of 360 N is being applied on the box and since the box did not disconnect from the rope, the rope applied the same amount of force in the opposite direction</em>
Therefore tension on the force = <u>360 N</u>
Answer:
For a plant cell: The cell wall and the cell membrane
For animal cells: Just the cell membrane
Answer:
B
Explanation:
Acceleration = rate of change in velocity
a = (21-12)/(0.45) = 20cm/s^2
