Motion in A Straight Line - Online Test

Q1. A truck is coming towards you from a distance of 1000m on a straight road at time t=0. At time t=10 seconds it is at a distance of 900 m. The average velocity in m/sec is
Answer : Option C
Explaination / Solution:

Initial distance x​​​​​​1 = 1000m

Initial time t​​​​​​1= 0 sec

Final distance x​​​​​​2 = 900 m

Final time t​​​​​​2 = 10 sec

Average velocity 


Q2. A truck is coming towards you from a distance of 1000m on a straight road, at time t=0. It reaches you in 100sec. The average speed in m/s is
Answer : Option D
Explaination / Solution:

Total distance covered s = 1000 m

Total time taken t = 100-0 = 100 s

Average speed 


Q3. A truck is coming towards you from a distance of 1000m on a straight road, at time t=0. The driver stops for a second near a poster. He reaches you in 100 sec. The average speed in m/s is
Answer : Option A
Explaination / Solution:

Total distance covered s = 1000 m

Total time taken t = 100-0 = 100 s

Average speed 


Q4. A truck is coming towards you from a distance of 1000m on a straight road. At time t=0 it starts from rest. At time t=10 seconds its velocity is 20m/s. What is the average acceleration in m/ 
Answer : Option A
Explaination / Solution:

Average acceleration is the change in velocity divided by an elapsed time.

Initial velocity u = 0 m/s

Final velocity v = 20 m/s

Time elapsed = 10-0 = 10 s

Average acceleration 


Q5. With reference to the figure which shows a particle moving along a straight line , y axis represents the position and x axis represents time, if  = 18m, The average velocity at if  in m/s is

Answer : Option A
Explaination / Solution:

Average velocity can be defined as the displacement divided by the time.

Total displacement d = 18 m

Time taken t = 1 s

average velocity 


Q6. A bus start from rest with an acceleration of 1 m/sec2. A man who is 48 meter behind the bus with a uniform velocity of 10 m/sec. then the minimum time after which the man will catch the bus is
Answer : Option A
Explaination / Solution:

Let the distance traveled by the bus when man catch the bus be S meter distance traveled by the man when he catch the bus S'=S+48 meter

Given :

Initial velocity of bus u=0

Initial velocity of man u'=10m/sec Acceleration of Bus=1 m/s2 

Accelerationof Man=0

We will use formula for displacement


By substituting the values in above equation we get,

Displacement of Bus 

Displacement of Man 

By substituting the value of S from eq(1) in eq(2)we get





=> t = 8, 12

Taking minimum value t = 8 sec


Q7. A stone thrown from the top of a building is given an initial velocity of 20.0 m/s straight upward. Determine the time in seconds at which the stone reaches its maximum height. g =9.8 m / 
Answer : Option D
Explaination / Solution:

Initial velocity u = 20.0 m/s

At maximum height it ll stop

So final velocity v = 0 m/s

Acceleration due to gravity g = 9.8 m/s​​​​​​2

Time taken to reach maximum height = t

We know

v = u + at

=> 

 s [g is taken negative because it is in opposite direction of motion.]


Q8. With reference to the figure below which shows a particle moving along a straight line , y axis represents the position and x axis represents time, if = 270m, The instantaneous velocity at  in m/s is

Answer : Option B
Explaination / Solution:

Instantaneous speed is the slope of the line at that point.

According to given image 

Slope of line at x​​​​​​2 = 

= 122.7 


Q9. Motion along a straight line is called __________.
Answer : Option A
Explaination / Solution:

Rectilinear motion is another name for straight-line motion. This type of motion describes the movement of a particle or a body. A body is said to experience rectilinear motion if any two particles of the body travel the same distance along two parallel straight lines.

Q10. A jet lands on an aircraft carrier at 60 m/s. What is its acceleration if it stops in 2.0 s?
Answer : Option A
Explaination / Solution:

Initial velocity u = 60 m/s

As it stops then final velocity v = 0 m/s

Time taken t = 2.0 s

We know,

v-u = at

=> 0-60= 2a

=> a = 

-ve sign shows velocity is decreasing.