Answer:
The size of the force that pushes the wall is 12,250 N.
Explanation:
Given;
mass of the wrecking ball, m = 1500 kg
speed of the wrecking ball, v = 3.5 m/s
distance the ball moved the wall, d = 75 cm = 0.75 m
Apply the principle of work-energy theorem;
Kinetic energy of the wrecking ball = work done by the ball on the wall
¹/₂mv² = F x d
where;
F is the size of the force that pushes the wall
¹/₂mv² = F x d
¹/₂ x 1500 x 3.5² = F x 0.75
9187.5 = 0.75F
F = 9187.5 / 0.75
F = 12,250 N
Therefore, the size of the force that pushes the wall is 12,250 N.
Answer:
star
Explanation:
because that is what our sun is.
Answer:
3099 J
Explanation:
The increase in thermal energy corresponds to the mechanical energy lost in the process.
The mechanical energy is given by the sum of gravitational potential energy and kinetic energy of the fireman:

At the top of the pole, the fireman has no kinetic energy, so all his mechanical energy is just potential energy:

When the fireman reaches the bottom, he has no gravitational potential energy, so his mechanical energy is just given by his kinetic energy:

So, the loss in mechanical energy was

and this corresponds to the increase in thermal energy.
Answer:
Final speed of striped ball is 3 m/s in left direction .
Explanation:
Given :
Two billiard ball with the same mass moves toward the left at the same speed 3 m/s .
Let , us assume right hand side direction to be positive and left hand side direction to be negative .
Also , let speed of ball after collision is (striped ball ) u and (solid ball) v .
It is also given that the collision is elastic .
Therefore , kinetic energy is conserved .
...... ( 1 )
Also , by conserving linear momentum .
We get :
...... ( 2 )
Putting value of u from equation 2 to equation 1 .
We get :

And , u = -3 m/s .
Therefore , final speed of striped ball is 3 m/s in left direction .
Hence , this is the required solution .
Speed = distance / time
3.4cm / 0.1s = 34 cm/sec