Question

Reena is riding a motorised scooter along a straight
path. The combined mass of Reena and her scooter
is 80 kg. The frictional forces that are acting total
to 45 N. What is the magnitude of the driving force
being provided by the motor if
(a) she is moving with a constant speed of
10 m s-1?
(b) she is accelerating at 1.5 m s-2?
Two athletes on a team, A and B, are practising to​

Answer 1

Answer:

(a) F - 45 = ma

F- 45 =0

F =45N

(b) F- 45 = 80 ×1.5

F = 45 +120

F = 165 N

Answer 2

Answer:

• Combined mass of Reena and Scooter = 80 kg

frictional force = -45 N (because the surface of one object comes in contact with the surface of another that's why it is -ve )

speed (u) =10m/s

so Acceleration = 0 (because speed  is constant)

a) Force = ma

-45 =80 * 0

-45 = 0

F = 45 N

b) acceleration = 1.5ms-2 (given)

Force = ma

-45 = 80*1.5

F= 45 + 120

F= 165 N