Question

A block of mass 5 kg at rest is given a constant power of 20 watt . find its speed after 5 second resistance , assuming no resistance available.​

Answer 1

Answer :

→ V = √(40) m/sec.

Explanation:

See the attachment. .. .. .. .. .

Hence, it is solved.

Answer 2

Given

p = 20w

mass = 5kg

time = 5second

Assumed resistance is negligible

Find

speed =?

we know that

p = w/time

20W = W/5

w = 100j

we know that work = force * displacement

and F= ma

where displacement = s

FS = 100j

mas = 100j

as = 20m^2/s ^2

Now

v^2 = u^2 + 2as

v^2= 40m^2/s^2

v = sqrt40m/s

so speed = sqrt40 m/s