Answer:
The total momentum before and after collision is 72000 kg-m/s.
Explanation:
Given that,
Mass of car = 1200 kg
Velocity of car = 10 m/s
Mass of truck = 2000 kg
Velocity of truck = 30 m/s
Using conservation of momentum
The total momentum before the collision is equal to the total momentum after collision.
Where, 
=mass of car
=velocity of car
=mass of truck
=velocity of truck
Put the value into the formula
Now, The total momentum before collision is
The total momentum after collision is
Hence, The total momentum before and after collision is 72000 kg-m/s.
Explanation:
here u = 50m/s
v = 60m/s
t = 58 s
then a = (60-50)/58 m/s2
= 0.17m/s2
now s= ut+1/2at2
so , 50×58+0.5×0.17×(58)^2 m
= 3185.94 m
= 3.18 km
List out all the variables that you do know;
acceleration=-9.8 ms⁻¹ (this remains constant on Earth)
Final velocity=?
Displacement (s)= -2.1 m
Initial Velocity(u)=2.5 ms⁻¹
v²=u²+2as
v²=(2.5)²+2(-9.8)(-2.1)
v²=47.41
v=√47.41
v=6.88549 ≈ 6.9 ms⁻¹
Hope I helped :)
Average acceleration over a time interval lasting 
is
where 
is the difference in the jet's final and initial velocities. It's coming to a rest, so
so the average acceleration has magnitude 8.9 m/s^2 and is pointing West (the direction opposite the jet's movement, which should make sense because the jet is slowing down).
Rubber. The other three are metals, and therefore good conductors.
