VII B SCIENCE 12 MOTION AND TIME (EXAMPLE WORKSHEET )

 

ANSWERS 

1)A car takes 90 minutes to reach the hospital. The odometer of the car shows that
the car has covered a distance of 20 km. What is the speed of the car in km/hr.

 

 

Time (t) = 90 minutes= 90/60 hours = 1.5 hours
Distance (d) = 20 km
To find out: Speed (s) =?
Solution: total distance covered (d)speed = total time taken (t)

Substituting the given values in the formula of speed, we get,
d 20s = = = 13.33 km/ ht 1.5


Therefore, the speed of car is 13.33 km/h.

 

2)Raju drove his car to go to his friend’s house at a speed of 10 km/h and this
journey took him 3 hours. How far did he travel?

 

 

Speed (s) = 10 km/h
Time (t) = 3 hours
To find out: Distance (d) =?
Solution:
As we know, total distance covered (d)speed = total time taken (t)

Rearranging the above equation, we get
d= s x t

Substituting the given values in the above equation, we get,
d = 10 x 3
=30 km

Therefore, the distance travelled is 30 km. 

 

 

3)A school bus travels at 30 km/h to cover a distance of 20 km. How much time (in
minutes) will the bus take to cover this distance?

 

 

Speed (s) = 30 km/h
Distance (d) = 20 km
To find out: Time (t) =?
Solution: total distance covered (d)speed = total time taken (t)

Rearranging the above equation, we get
dt = s
Substituting the given values in the above equation, we get, 20t = 30
= 0.67 hours
if we convert hours into minutes, we get
t= 0.67 x 60 = 40.2 minutes
Hence, the bus will take 40.2 minutes to cover the distance of 20 km.

Or 20t = 30
 60 minutes = 40 minutes (to cover the distance of 20 km)

 

4)  Aman can run a distance of 100 m in 20 seconds. Find the speed of Aman in m/s.

 

 

Time (t) = 20 seconds
Distance (d) = 100 m
To find out: Speed (s) =?
Solution: total distance covered (d)speed = total time taken (t)

Substituting the given values in the formula of speed, we get,
100 520
ds = = = m/ st


Therefore, the speed of Aman is 5 m/s.  

 

 

5) 

An aeroplane covers a certain distance at a speed of 240 km/h in 5 hours.
Calculate the distance covered.

 

Speed (s) = 240 km/h
Time (t) = 5 hours
To find out: Distance (d) =?
Solution:
As we know, total distance covered (d)speed = total time taken (t)

Rearranging the above equation, we get
d= s x t

Substituting the given values in the above equation, we get,
d = 240 x 5
=1200 km

Therefore, the distance travelled is 1200 km. 

 

6) 

Traveling at a speed of 50 km/h, how many hours will Manoj take to travel 60
km?

 

Speed (s) = 50 km/h
Distance (d) = 60 km
To find out: Time (t) =?
Solution: total distance covered (d)speed = total time taken (t)

Rearranging the above equation, we get
dt = s
Substituting the given values in the above equation, we get, 60t = 50
= 1.2 hour
Hence, Manoj will take 1.2 hours to cover the distance of 60 km.