Question

a scooter covers a distance of 3 kilometres in 5 minutes. calculate its speed in cm/sec, m/sec, km/hr??? Of Physics class 9th CBSE​

Answer 1

$\textbf{Answer: 1000cm/sec, 100m/sec and 36km/hr }$

Given,

Distance = 3km

Time = 5 Minutes

Speed = ?

$\textbf{We know the formula of speed,}$


Speed = Distance/Time

Speed = 3km / 5min

We will convert 3km in Metres and centimeters first,

3km in Meters = 3 × 1000 = 3000m

3km in centimeters = 3 × 10000 = 30000cm

Time = 5 minutes = 300 second

$\textbf{Explanation:- }$


1) $\textbf{In centimeters }$


Speed = Distance/Time

Speed = 30000/300

Speed = 1000cm/sec

2) $\textbf{ In meters}$


Speed = Distance/Time

Speed = 3000/300

Speed = 100m/sec


3) $\textbf{In km/hr }$


Speed = Distance/Time

Speed = 3 km and 5 min = 1/12 h

Speed = 3*12/1 = 36 km/h

Speed = 36km/hr

Answer 2

1 km=1000 m

1000 m=100×1000=100000 cm

1hour=60 min

1 min=1×60=60 seconds

In cm/sec

3 km=3000m

3000m=300000 cm

5min=60×5=300 seconds

Speed=Distance/Time

=300000/300

=1000 cm/sec

In m/s

3 km=3000 m

5 minutes=300 s

Speed=3000/300

=10 metre/ second

In km/h

Distance=3km
Time=5 min=5/60 hours

=1/12 hours

Speed=3÷1/12
=3×12
=36 km/h