Answer:
390 J
Explanation:
m = 3 kg
u = 16 i + 2 j
(a) Magnitude of velocity = 
= 16.1245 m/s
KEi = 1/2 m v^2 = 0.5 x 3 x 16.1245 = 390 J
(b) v = 18 i + 14 j
Magnitude of velocity = 
= 22.804 m/s
KEf = 1/2 m v^2 = 0.5 x 3 x 22.804 = 780 J
According to the work energy theorem
Work done = change in KE = KEf - KEi = 780 - 390 = 390 J
Explanation:
increase the distance of cube from black and dull substance
It is Yellow, Cyan, Magenta . The answer is D.
Answer = 30,000 N
EXPLANATION
Applying Newton’s second of law of motion, which in summary, states that t<span>he acceleration of an object... is directly proportional to the magnitude of the net force... and inversely proportional to the mass of the object.
</span><span>
Therefore, Force = Mass * Acceleration
F = ma
Mass, m = </span><span>3,000 kg
</span>Acceleration, a = <span>10 m/s</span>²<span>
</span>Force, F = 3,000 × 10
= 30,000 N
Before we find impulse, we need to find the initial and final momentum of the ball.
To find the momentum of the ball before it hit the floor, we need to figure out its final velocity using kinematics.
Values we know:
acceleration(a) - 9.81m/s^2 [down]
initial velocity(vi) - 0m/s
distance(d) - 1.25m [down]
This equation can be used to find final velocity:
Vf^2 = Vi^2 + 2ad
Vf^2 = (0)^2 + (2)(-9.81)(-1.25)
Vf^2 = 24.525
Vf = 4.95m/s [down]
Now we need to find the velocity the ball leaves the floor at using the same kinematics concept.
What we know:
a = 9.81m/s^2 [down]
d = 0.600m [up]
vf = 0m/s
Vf^2 = Vi^2 + 2ad
0^2 = Vi^2 + 2(-9.81)(0.6)
0 = Vi^2 + -11.772
Vi^2 = 11.772
Vi = 3.43m/s [up]
Now to find impulse given to the ball by the floor we find the change in momentum.
Impulse = Momentum final - momentum initial
Impulse = (0.120)(3.43) - (0.120)(-4.95)
Impulse = 1.01kgm/s [up]
