A train of mass 1600 kg attains a speed of 25 ms\(^{-1}\) in 20 seconds. The power developed in the engine is?
2.5 KW
80 KW
25 KW
50 KW
Explanation
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p=wd/t
wd=1/2mv^2
=1/2*1600*25^2
=500,000j
p=500,000/20
=25kw
myschool.ng pls make corrections
To calculate the power developed in the engine, we can use the formula:
Power = Force x Velocity
First, we need to calculate the force acting on the train. We can use the formula:
Force = Mass x Acceleration
Given that the mass of the train is 1600 kg and it attains a speed of 25 m/s in 20 seconds, we can calculate the acceleration:
Acceleration = Change in Velocity / Time
Acceleration = (25 m/s - 0 m/s) / 20 s
Acceleration = 1.25 m/s^2
Now, we can calculate the force:
Force = 1600 kg x 1.25 m/s^2
Force = 2000 N
Finally, we can calculate the power:
Power = Force x Velocity
Power = 2000 N x 25 m/s
Power = 50000 W
Therefore, the power developed in the engine is 50 kW, which corresponds to option D.
The answer is 25KW. Because even with this formula used, you should always remember to divide by 2 when there is a change in velocity. V and U. even when U is 0!!!
The easy peasy formula here is: P = mv² / t
Just find out about the formula and all this will be easy for u. 
why the turmoil.
Mass= 1600kg
v= 25 m/s
t= 20sec
lets find the acceleration
a= v/t
substitute 25 for v and 20 for t
a= 25/20
a= 1.25 m/s²
we have gotten our acceleration
remember
F= ma
f=?
mass= 1600kg
a= 1.25 m/²
f= 1600× 1.25
f=2000N
then remember again that
power =fv
p= ?
f= 2000
v=25
p=( 2×10^3) × (2.5×10^1)
p= 5× 10^4w
which is the same thing as 50kw
the answer is not correct they are missing something it's supposed to be halfmv square not mv square if it to attain a speed then the formula will be half mv square
P=W/t
Where W=F×s
F=ma
Using v=u+at
a=(v-u)/t=(25-0)/20=1.25
S=ut+1/2at²
S=0.5×1.25×20²=250
P=(1600×1.25×250)/20
P=25 000=25kw
