Question

a constant retarding force of 10N is exerted to a body of mass 20 kg moving initially with a speed of 10m/s. how long does the body take to stop ​

Answer 1

Hii..dude..♥️

Mass = 20 kg

Force = 10 N

u = 10 m/s

v = 0 m/s

Retardation (a) = F / m

=> a = 10/20

=> a = 1/2

=> a = 0.5 m/s^2

Since it is retardation hence the acceleration will become negative bacause it's decreasing .

=> a = - 0.5 m/s^2

Now use the first equation of motion ,

v = u + at

=> 0 = 10 + (-0.5) t

=> 0 = 10 - 0.5 t

=> 10 - 0.5 t = 0

=> 10 = 0.5 t

=> t = 10 / 0.5

=> t = 20 seconds

hope this helps...✨✨☑️

Answer 2

Answer:

Mass = 20 kg

Force = 10 N

u = 10 m/s

v = 0 m/s

Retardation (a) = F / m

=> a = 10/20

=> a = 1/2

=> a = 0.5 m/s^2

Since it is retardation hence the acceleration will become negative bacause it's decreasing .

=> a = - 0.5 m/s^2

Now use the first equation of motion ,

v = u + at

=> 0 = 10 + (-0.5) t

=> 0 = 10 - 0.5 t

=> 10 - 0.5 t = 0

=> 10 = 0.5 t

=> t = 10 / 0.5

=> t = 20 seconds

Explanation: