Question

39. Distinguish between speed and velocity.
A scooter starts from rest moves in a straight line with constant acceleration
and covers a distance of 64km in 4 sec Calculate its acceleration and final
velocity..​

Answer 1

Answer:

speed is a scalar quantity while velocity is a vector quantity

in given question

u=0

s=64km=600

t=4s

s=ut+1/2 (at^2)

6400=0+1/2 (a×16)

a=800m/s^2

v^2-u^2=2 as

v^2=2×800×6400

v=40×80

v=3200m/s

Answer 2

Answer:

1.speed is related to distance while velocity is related to displacement.

2.The units of speed and velocity is same.In SI system,the unit is m/s while in CGS system , it is cm/s.

3.If the motion is along a straight line,the value of speed and velocity are the same,otherwise they can be different.

Explanation:

initial velocity=0

finial velocity=v

distance = 64km

time= 4sec

for find acceleration,

S = Ut+1/2 at2

64= 0×4+1/2a4×4

64 = 0 + 1/2 a 16

64 = 1 × a × 4

64/4 = a

8 = a

acceleration = 8cm/s

for velocity,

a = v-u÷t

8 = v - 0 ÷ 4

8 × 4 = v

32 = v

velocity = 32cm/ s