Answer:
80%
Explanation:
Efficiency = Power output / Power input × 100 %
To calculate efficiency we need to find power output of electric pump.
We can use,
Work done = Energy change
Work done per second = Energy change per second
Work done per second = Power
Therefore, Power = Energy change per second
= Change in potential energy of water per second
=mgh / t
= 200× 10×6 / 10
= 1200 W = 1.2 kW
Now use the first equation to find efficiency,
Efficiency =
× 100%
= 80 %
The acceleration of the car is 0.8049
.It takes 13.802s to travel the 230 m.
<h3>
What is acceleration?</h3>
In mechanics, acceleration refers to the rate at which an object's velocity with respect to time varies. Acceleration is a vector quantity (in that they have magnitude and direction). The direction of an object's acceleration is determined by the direction of the net force acting on it. Newton's Second Law states that the combined effect of two factors determines how much an item accelerates:
(i) It follows that the magnitude of the net balance of all external forces acting on the object is directly proportional to the magnitude of this net resulting force, and
(ii) the mass of the thing, depending on the materials out of which it is constructed, is inversely proportional to the mass of the thing.
Calculations:
40 km/hr ----- 11.11m/s
80 km/hr ----- 22.22m/s

Time taken
v-u=at
22.22-11.11= 0.8049 x t
t=13.802s
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Answer:
This is an open circuit
Explanation:
An open circuit I believe
It needs to be closed for the bulb to be turned on
Self productive and it depends on how whom is behaving.
Assuming that all the bullet’s energy heats the paraffin, its final temperature is 27.1 degree C. The correct option is D.
<h3>What is temperature?</h3>
Temperature is the degree of hotness and coldness of the material.
The energy of the bullet E = 1/2 mv²
E = 1/2 x 10 x 10⁻³ x (2000)²
E = 2 x 10⁴ J
This heat is used in heating the paraffin
E = m x c ΔT = m x c (Tfinal -Tinitial)
2 x 10⁴ J = 1 x 2.8 x 10³ x (Tfinal -20)
Tfinal = 27.1°C
Thus, the final temperature is 27.1 degree C. The correct option is D.
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