Answer:
35 km/hr
Explanation:
Average speed = (total of the speed)/(the sets of speeds given)
Direction does not matter in this instance since speed is only magnitude,
Average speed = (30 + 40)/2
Average speed = 70 ÷ 2
= 35 km/hr
Answer:
wrong statement : Momentum is not conserved for a system of objects in a head-on collision.
Explanation:
In a head on collision of two objects , two equal and opposite forces are created at the point of collision . These two forces create two impulses in opposite direction which results in equal and opposite changes in momentum in each of them . Hence net change in momentum is zero. In this way momentum is conserved in head on collision of two objects.
Strong Nuclear force: it is the short range force and strongest fundamental force in all type of forces.
Electromagnetism: this is the force due to magnetic and electric behavior of the particles. It is moderate type of force and its range is more than Nuclear force.
Weak Nuclear Force: This force is also short range force which act between the nucleoside. But this force is also moderate type of force
Gravitational force: this force is between two point masses and least order of force. also the range of this force is upto infinite.
so the correct order of this fundamental force is
<em>strong nuclear, electromagnetism, weak nuclear, gravitational</em>
