Question

a) Distinguish between speed and velocity. Under what condition(s) is the magnitude of
average velocity of an object equal to its average speed?
b) Starting from a stationary position, Rahul paddles his bicycle to attain a velocity of 6 m/s
in 30 s. Then he applies brakes such that the velocity of the bicycle comes down to 4 m/s in
the next 5 s. Calculate the acceleration of the bicycle in both the cases,​

Answer 1

Answer:

a.

• Speed is scalar while velocity is a vector quantity
• Speed is always positive while velocity can be positive, zero and negative.
• The magnitude of average velocity of an object is equal to its average speed only when the object moves in a straight line.

b. 1st case :

a= 1/5 = 0.2 m/s²

2nd case :

a = -4/5 m/s² = -0.8 m/s²