Answer:
96%
Explanation:
To find the values of the motor efficiency you use the following formula:

P_o: output power = 864J/0.5min=864J/30s=28.8W
P_i: input power = I*V = (3A)(12V) = 36W
By replacing this values you obtain:

hence, the motor efficiency is about 96%
traslation:
Pentru a găsi valorile eficienței motorului, utilizați următoarea formulă:
P_o: putere de ieșire = 864J / 0.5min = 864J / 30s = 28.8W
P_i: putere de intrare = I * V = (3A) (12V) = 36W
Înlocuind aceste valori obțineți:
prin urmare, eficiența motorului este de aproximativ 96%
Answer:
Part a)

Part b)
Direction = upwards
Explanation:
When ball is dropped from height h = 4.0 m
then the speed of the ball just before it will strike the ground is given as



Now ball will rebound to height h = 2.00 m
so the velocity of ball just after it will rebound is given as



Part a)
Average acceleration is given as



Part B)
As we know that ball rebounds upwards after collision while before collision it is moving downwards
So the direction of the acceleration is vertically upwards
Answer:
90-100meters
Explanation:
The overall length limitation of a UTP cable is 90-100meters. Once this limitation is reached, a repeater is employed to transfer data.
Answer:
V is approximately = 23m/s
Explanation:
Kinetic energy = ½ mv²
Where m= mass = 0.450kg
V= velocity =?
K. E = 119J
Therefore
K. E = ½ mv²
Input values given
119= ½ × 0.450 × v²
Multiply both sides by 2
119 ×2 = 2 × 1/2 × 0.450 × v²
238= 0.450v²
Divide both sides by 0.450
238/0.450 = 0.450v²/0.450
v² = 528.89
Square root both sides
Sq rt v² = sq rt 528.89
V = 22.998m/s
V is approximately = 23m/s
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