Certain force acting on a 20kg mass changes it's velocity from 5m)sec

1.	Certain force acting on a 20kg mass changes it's velocity from 5m)sec to 2m/sec. Calculate the work done by the force?
Answer» Answer: Hey mate here is ur answer MARK it as brainliest Explanation: here , GIVEN mass = 20 kg initial velocity (u) = 5 m/sec final velocity (v) = 2 m/sec time (t)= 1sec so , from first equation of motion v= u+ at or, a= ( v- u) / t a= ( 2 ms-¹ - 5 ms-¹) / 15 a= - 3 ms-² therefore, from third equation of motion v²- u²= 2as = ( 2ms -1 )² - ( 5ms-¹) ² = 2× (-3ms-²) ×5 = -21 m²s² = -6ms-²× 5 = s = 7/2 METRE =3.5 m therefore, we KNOW , workdone= f × s and , F = m× a so, work = m× a× s = 20 kg × ( -3ms-²) × 7/2m = - 210 joules.

Certain force acting on a 20kg mass changes it's velocity from 5m)sec to 2m/sec. Calculate the work done by the force?

Answer»

Answer:

Hey mate here is ur answer MARK it as brainliest

Explanation:

here , GIVEN mass = 20 kg

initial velocity (u) = 5 m/sec

final velocity (v) = 2 m/sec

time (t)= 1sec

so , from first equation of motion

v= u+ at

or, a= ( v- u) / t

a= ( 2 ms-¹ - 5 ms-¹) / 15

a= - 3 ms-²

therefore, from third equation of motion

v²- u²= 2as

= ( 2ms -1 )² - ( 5ms-¹) ²

= 2× (-3ms-²) ×5

= -21 m²s² = -6ms-²× 5

= s = 7/2 METRE =3.5 m

therefore, we KNOW ,

workdone= f × s

and , F = m× a

so, work = m× a× s

= 20 kg × ( -3ms-²) × 7/2m

= - 210 joules.

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