We can do this with the conservation of momentum. The fact it is elastic means no KE is lost so we don't have to worry about the loss due to sound energy etc.
Firstly, let's calculate the momentum of both objects using p=mv:
Object 1:
p = 0.75 x 8.5 = 6.375 kgm/s
Object 2 (we will make this one negative as it is travelling in the opposite direction):
p = 0.65 x -(7.2) = -4.68 kgm/s
Based on this we know that the momentum is going to be in the direction of object one, and will be 6.375-4.68=1.695 kgm/s
Substituting this into p=mv again:
1.695 = (0.75+0.65) x v
Note I assume here the objects stick together, it doesn't specify - it should!
1.695 = 1.4v
v=1.695/1.4 = 1.2 m/s to the right (to 2sf)
Answer:
It is unsafe
Explanation:
v = Velocity of car = 34 m/s
r = Radius of turn = 190 m
= Coefficient of static friction = 0.5
m = Mass of car = 1600 kg
g = Acceleration due to gravity = 9.81 m/s²
The centripetal force is given by

The frictional force is given by

If the centripetal force is greater than the frictional force then the car will slip which makes it unsafe.
Here, the centripetal force is greater than the frictional force which makes it unsafe to drive it at that speed.
Newtons Law of motion
HOPE IT HELPS:)
Answer:
No, the truck will not cross the barrier.
The closeness of the truck to the barrier is of 21.875 m
Solution:
As per the question:
Velocity of the truck, v = 25.0 m/s
Acceleration of the truck, a = - 4 
Now,
Since, the barrier at a distance of 100 m. Thus in order to check whether the truck hit the barrier or not, we will see the distance, d it covers by using the kinematic eqn:

Final velocity, v' = 0 m/s
Initial velocity = v
Now,


d = 78.125 m
Thus the truck will not cross the barrier.
Distance between the barrier and the truck:
100 - 78.125 = 21.875 m