Answer: Work done = 153.125Joules, Work done = 0.003Nm
Explanation:
Kinetic energy of a body is the energy possessed by a body by virtue of its motion.
Mathematically,
K.E = 1/2MV²
Where;
M = mass of the body = 2.5g = 0.0025kg
V = velocity of the body = 350m/s
Substituting this values in the formula, we have;
K.E = 1/2× 0.0025×350²
K.E = 153.125Joules
Work done is the force applied to body to cause it to move through a distance.
Work = Force × distance
Force = ma = 0.0025 × 10
Force = 0.025N
Distance = 12cm = 0.12m
Work = 0.025×0.12
Work = 0.003Nm
work done by the tree in stopping the bullet is 0.003N
Answer:
Option C - 39.2 J
Explanation:
We are given that;
Mass; m = 2 kg.
Distance moved off the floor;d = 10 m.
Acceleration due to gravity;g = 9.8 m/s².
We want to find the work done.
Now, the Formula for work done is given by;
Work = Force × displacement.
In this case, it's force of gravity to lift up the boots, thus;
Formula for this force is;
Force = mass x acceleration due to gravity
Force = 2 × 9.8 = 19.2 N
∴ Work done = 19.6 × 2
Work done = 39.2 J.
Hence, the Work done to life the boot of 2 kg to a height of 2 m is 39.2 J.
Answer:

Explanation:
Using the conservation of energy we have:

Let's solve it for v:

So the speed at the lowest point is 
Now, using the conservation of momentum we have:

Therefore the speed of the block after the collision is 
I hope it helps you!
Answer:17.08 s
Explanation:
Given
distance between First and second Runner is 45.6 m
speed of first runner
=3.1 m/s
speed of second runner
=4.65 m/s
Distance between first runner and finish line is 250 m
Second runner need to run a distance of 250+45.6=295.6 m
Time required by second runner 
time required by first runner to reach finish line
Thus second runner reach the finish line 80.64-63.56=17.08 s earlier