Answer: 2000 watts
Explanation:
Given that,
power = ?
Weight of object = 200-N
height = 4 m
Time = 4 s
Power is the rate of work done per unit time i.e Power is simply obtained by dividing work by time. Its unit is watts.
i.e Power = work / time
(since work = force x distance, and weight is the force acting on the object due to gravity)
Then, Power = (weight x distance) / time
Power = (200N x 4m) / 4s
Power = 8000Nm / 4s
Power = 2000 watts
Thus, 2000 watts of power is needed to lift the object.
Answer:
(a) 2.5 m/s
(b) 37.5 KJ
Explanation:
(a)
From the law of conservation of momentum, Initial momentum=Final momentum

and making
the subject then
and since
is initial velocity of car, value given as 4 m/s,
is the initial velocity of the three cars stuck together, value given as 2 m/s and
is the final velocity which is unknown. By substitution

(b)
Initial kinetic energy is given by

Final kinetic energy is given by

The energy lost is given by subtracting the final kinetic energy from the initial kinetic energy hence
Energy lost=350-312.5=37.5 KJ
Answer:
Explanation:
KE = ½Iω²
ΚΕ = ½(mL²/3)ω²
ΚΕ = ½(0.63(0.82²)/3)4.2²
ΚΕ = 1.24541928
KE = 1.2 J
Answer:
170 N
Explanation:
Given in the question that, work a bulldozer can do = 4500 J
<h3>
Step 1</h3>
We will use trigonometry identity to find the distance bulldozer will travel up the hill
sin(35) = opp/hypo
sin(35) = 15/hypo
hypo = 15/sin(35)
hypo = 26.15m
<h3>Step 2</h3>
Formula to use
work done = force × distance
Plug values in the above formula
4500 = force x 26.15
force = 4500/26.15
force = 172.08
force ≈ 170 N
<h3 /><h3 /><h3 />
Answer:
In an inductive circuit, when frequency increases, the circuit current decreases and vice versa.
Explanation: