Answer:
The work required is -515,872.5 J
Explanation:
Work is defined in physics as the force that is applied to a body to move it from one point to another.
The total work W done on an object to move from one position A to another B is equal to the change in the kinetic energy of the object. That is, work is also defined as the change in the kinetic energy of an object.
Kinetic energy (Ec) depends on the mass and speed of the body. This energy is calculated by the expression:

where kinetic energy is measured in Joules (J), mass in kilograms (kg), and velocity in meters per second (m/s).
The work (W) of this force is equal to the difference between the final value and the initial value of the kinetic energy of the particle:


In this case:
- W=?
- m= 2,145 kg
- v2= 12

- v1= 25

Replacing:

W= -515,872.5 J
<u><em>The work required is -515,872.5 J</em></u>
Answer:
power is given by work done divide time taken
P=w/t
therefore Pt=w
270x42=11,340.J
Answer:
three balls have the same speed
Explanation:
In a parabolic motion we have that

but the time just before the balls hit the ground is

Hence we have
ball A

ball B

ball C

Hence, all three balls have the same speed just before hit the groug
vA=vB=vC
I hope this is useful for you
regards
Answer:
W = 819152 J = 819.15 KJ
Explanation:
The work done by Juri can be given by the following formula:

where,
W = Work done = ?
F = Force = 200 N
d = distance = 5 km = 5000 m
θ = angle to horizontal = 35°
Therefore,
W = (200 N)(5000 m)Cos 35°
<u>W = 819152 J = 819.15 KJ</u>
as it is given that curved marked the speed as v = 70 km/h
so we will first convert the speed into m/s

now we know that here friction force will provide centripetal force

As we know that centripetal force is given as






