Question

pls answer properly....
3. A 1 kg mass at rest is subjected to an
acceleration of 5 m/s2 and travels 40m. The
average power during the motion is
1) 40W 2) 8W 3) 50W 4) 200W​

Answer 1

Given :-

m = 1kg

a = 5 m/s²

s = 40 m

accordingly to question,

=> s = ut + 1/2 at²

=> 40 = 0 × t + 1/2 ×5 × t²

=> t² = 16

=> so , t = 4 S

Now ,

•force act on body = 1× 5 = 5 N

•so, work done = 40× 5 = 200 J

•average power = total work done / total time

=> average power = 200/4 = 50 W

Answer 2

Answer:

2as=v

2

−u

2

⇒2×5×40=v

2

−u

2

⇒v

2

−u

2

=400

(2) s=ut+

2

1

at

2

⇒t=4 sec

Power =

t

Work Done

=

t

Δ(K.E)

=

t

2

1

m(v

2

−u

2

)

=

2

1

×

4

1×400

=50 W