Answer:
d = 100.8 ft
Explanation:
As we know that initial speed of the van is 40 miles then the stopping distance is given as 70 feet
here we know that

so here we have

now again if the speed is increased to 48 mph then let say the stopping distance is "d"
so we will have

now divide the above two equations


Explanation:
The net force would be upwards since the kangaroo would have to overcome gravity to jump
Answer:

ΔK = 2.45 J
Explanation:
a) Using the law of the conservation of the linear momentum:

Where:


Now:

Where
is the mass of the car,
is the initial velocity of the car,
is the mass of train,
is the final velocity of the car and
is the final velocity of the train.
Replacing data:

Solving for
:

Changed to cm/s, we get:

b) The kinetic energy K is calculated as:
K = 
where M is the mass and V is the velocity.
So, the initial K is:



And the final K is:




Finally, the change in the total kinetic energy is:
ΔK = Kf - Ki = 22.06 - 19.61 = 2.45 J
Its when the animal repeats what it is taught similar to a child you never really teach them to lie it just happens because they have seen other people do it
Answer:
Lifting a bag of groceries