The distance travelled by the object in 10 s

CBSE Class 9 CBSE Class 9 Science
1

Following graph represents the velocity-time graph of an object of mass 20 kg.
image
Find out

  1. the distance travelled by the object in 10 s.
  2. the force on object from t = 10stot = 15s.
2
  1. Since, we know that distance covered by a body,
    Distance = Area under velocity - time graph
    ∴ The distance covered by the object from t = 0 to t = 10 s.
    image
  2. From the graph, the object comes to rest at t =15s.
    Speed of the object at t = 10 s, u = 50 m/s
    Speed of the object at t = 15 s, v = 0
    and the time interval for change in speed, Δt = 15 - 10 = 5s
    ∴ Acceleration of the object, image
    Since, force, F = mass x acceleration = 20 x -10 = -200 N
    The negative sign implies that the force is in opposite direction to the velocity of the objecet.