Answer:
v = 1.25 m/s
Explanation:
We have,
Distance covered by a person is 10 meters
Time taken by him to cover that distance is 8 seconds.
If we want to find the speed of a person, we must know distance covered by it and taken. In this case, we know both distance and time. His speed is given by :
So, the speed of the person is 1.25 m/s.
2.71 m/s fast Hans is moving after the collision.
<u>Explanation</u>:
Given that,
Mass of Jeremy is 120 kg ()
Speed of Jeremy is 3 m/s ()
Speed of Jeremy after collision is () -2.5 m/s
Mass of Hans is 140 kg ()
Speed of Hans is -2 m/s ()
Speed of Hans after collision is ()
Linear momentum is defined as “mass time’s speed of the vehicle”. Linear momentum before the collision of Jeremy and Hans is
=
Substitute the given values,
= 120 × 3 + 140 × (-2)
= 360 + (-280)
= 80 kg m/s
Linear momentum after the collision of Jeremy and Hans is
=
= 120 × (-2.5) + 140 ×
= -300 + 140 ×
We know that conservation of liner momentum,
Linear momentum before the collision = Linear momentum after the collision
80 = -300 + 140 ×
80 + 300 = 140 ×
380 = 140 ×
380/140=
= 2.71 m/s
2.71 m/s fast Hans is moving after the collision.