Answer:
Correct answer: Third statement P = 4900 W
Explanation:
Given:
m = 500 kg the mass of the elevator
h = 10 m reached height after t = 10 seconds
P = ? power of the motor
The formula for the calculating power of the motor is:
P = W / t
since work is a measure of change in this case of potential energy then it is:
W = ΔEp = Ep - 0 = Ep
In this case we must take g = 9.81 m/s²
Ep = m g h = 500 · 9.81 · 10 = 49,050 W ≈ 49,000 W
Ep ≈ 49,000 W
P = Ep / t = 49,000 / 10 = 4,900 W
P =4,900 W
God is with you!!!
Multiply the masses by the respective distances:
(12 kg) (2 m) = 24 J
(25 kg) (1 m) = 25 J
so the heavier bag takes more work to lift, and (b) is the answer.
(d) is technically correct if the sacks are carrying different contents whose masses are not equal, but since we don't know what's inside each sack, assume 12 kg and 25 kg are the masses of each sack *and* their contents.
Answer:
v = 6t² + t + 2, s = 2t³ + ½ t² + 2t
59 m/s, 64.5 m
Explanation:
a = 12t + 1
v = ∫ a dt
v = 6t² + t + C
At t = 0, v = 2.
2 = 6(0)² + (0) + C
2 = C
Therefore, v = 6t² + t + 2.
s = ∫ v dt
s = 2t³ + ½ t² + 2t + C
At t = 0, s = 0.
0 = 2(0)³ + ½ (0)² + 2(0) + C
0 = C
Therefore, s = 2t³ + ½ t² + 2t.
At t = 3:
v = 6(3)² + (3) + 2 = 59
s = 2(3)³ + ½ (3)² + 2(3) = 64.5
Answer:
option E
Explanation:
the correct answer is option E
the direction of magnetic field will be found out with the help of right hand rule.
Put you palm in the direction of electric field and curl your finger in the direction of magnetic field which east direction.
now, the direction shown by the thumb will be the direction of magnetic field which comes out to be toward South direction.
Answer:
W = 0.060 J
v_2 = 0.18 m/s
Explanation:
solution:
for the spring:
W = 1/2*k*x_1^2 - 1/2*k*x_2^2
x_1 = -0.025 m and x_2 = 0
W = 1/2*k*x_1^2 = 1/2*(250 N/m)(-0.028m)^2
W = 0.060 J
the work-energy theorem,
W_tot = K_2 - K_1 = ΔK
with K = 1/2*m*v^2
v_2 = √2*W/m
v_2 = 0.18 m/s
