Answer:
The speed of the block is 8.2 m/s
Explanation:
Given;
mass of block, m = 2.1 kg
height above the top of the spring, h = 5.5 m
First, we determine the spring constant based on the principle of conservation of potential energy
¹/₂Kx² = mg(h +x)
¹/₂K(0.25)² = 2.1 x 9.8(5.5 +0.25)
0.03125K = 118.335
K = 118.335 / 0.03125
K = 3786.72 N/m
Total energy stored in the block at rest is only potential energy given as:
E = U = mgh
U = 2.1 x 9.8 x 5.5 = 113.19 J
Work done in compressing the spring to 15.0 cm:
W = ¹/₂Kx² = ¹/₂ (3786.72)(0.15)² = 42.6 J
This is equal to elastic potential energy stored in the spring,
Then, kinetic energy of the spring is given as:
K.E = E - W
K.E = 113.19 J - 42.6 J
K.E = 70.59 J
To determine the speed of the block due to this energy:
KE = ¹/₂mv²
70.59 = ¹/₂ x 2.1 x v²
70.59 = 1.05v²
v² = 70.59 / 1.05
v² = 67.229
v = √67.229
v = 8.2 m/s
Answer:
Explanation:
Flux through the coil = nBA , n is no of turns , B is magnetic flux and A a is area of the coli
= 200 x 5.6 x 10⁻⁵ x 11.8 x 10⁻⁴
= 13216 x 10⁻⁹ weber .
b ) When the coil becomes parallel to magnetic field , flux through it will become zero.
c ) e m f induced = change in flux / time
= 13216 x 10⁻⁹ / 4.9 x 10⁻²
= 2697.14 x 10⁻⁷ V
= 269.7 x10⁻⁶
269.7 μV.
Answer:
t = 5 hr
Explanation:
Let kali moves toward east with velocity= V₁= 40 km/ h
Mat moves toward west with velocity = V₂= 50 km/hr
As Klai left one hour earlier = t₁= 1 hr
distance traveled in 1st hour = s₁ = v * t = 40 * 1 = 40 km
Remaining distance = 400 - 40 = 360 km
As they move in the opposite directions:
Relative speed= 40 + 50 = 90 km/ h
s = v * t
⇒ t = s / v
⇒ t₂ = 360 / 90
⇒ t₂ = 4 hr
Total time = t = t₁ + t₂
t = 1 hr + 4 hr
t = 5 hr
Potential energy is first transformed into kinetic energy as she pedals, then gravitational as she coasts down the hill.
Distance = speed / time
speed = 95 m/s
time = 3 s
distance = 95 / 3 m
displacement = 95/3 m or 32 m (2 s.f.)
