Answer:8.69 m/s
Explanation:
Given
mass of Empty train 
velocity of car 
mass of Boulder 
Since no External force is acting therefore conserving Momentum
Train and boulder moves with same velocity after collision



Answer:
if i am not mistaken the volume is 7, because it only took that much space
24. 02 N force of friction acting on the box.
<h3 /><h3>What is force?</h3>
A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
Force = mass. acceleration
Force = (2.2).(3.2)
Force = 7.04 N
Total force applied is 31.06 N
Frictional force = 31.06 - 7.04
Frictional force = 24. 02 N
24. 02 N force of friction acting on the box.
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To learn more about force refer to the link:
brainly.com/question/13191643
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Answer:
a)W= - 47.19 J
b)47.19 J
Explanation:
Given that
Weight ,mg= 71.5 N
y= 1.84 m
H= 2.5
a)
The distance above the hand ,h= 2.5 - 1.84 m
h= 0.66 m
We know that gravitaional force act in the downward direction but the displacement is in upward direction that is why work done will be negative.
W= - m g h
W= -71.5 x 0.66 J
W= - 47.19 J
b)
The potential energy at initial position = m g y
The potential energy at final position = m g H
So change in the potential energy = m g H - m g y
= mg ( H- y)
=71.5 ( 2.5 - 1.84 ) = 47.19 J
Therefore change in the potential energy = 47.19 J
Displacement = final - initial
The formula most closely resembling that is delta = xf - xi