Question

read these expressions with break 10 maths them to the meanings break a lock does it mean a bit of bad luck to do or say something to start the conservation with someone who is being very quiet to remove one cell completely and finally from a situation to say the same thing over and over again used for wishing someone good luck especially before a performance used when the machine of vehicle stops working​read this

Answer 1

Answer:

with break 10 maths them to the meanings break a lock does it mean a bit of bad luck to do or say something to start the conservation with someone who is being very quiet to remove one cell completely and finally from a situation to say the same thing over and over again used for wishing someone good luck especially before a performance used when the machine of vehicle stops workingread

Answer 2

Answer:

Explanation:

Question 1 )

Given : -

mass = 20 kg

initial velocity (u) = 5 m/sec

final velocity (v) = 2 m/sec

time (t)= 1sec

Solution : -

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

therefore, we know ,

workdone= f × s

and , F = m× a

so, work = m× a× s

= 20 kg × ( -3ms-²) × 7/2m

= - 210 joules.

Hence the answer is - 210

Question ( 2 )

Given : -

v = 5m/s

K.E = 25 J

Solution : -

K.E = 1/2 mv^2

25 = 1/2 m (5)^2

25 x 2 = 25m

m = 2 kg

Now if the velocity becomes 3 times then the velocity is 3 x 5 = 15m/S

Now new K.E = 1/2 x 2 x 15^2

= 225 J

Answer is 225 j