Answer:
a) k = 2231.40 N/m
b) v = 0.491 m/s
Explanation:
Let k be the spring force constant , x be the compression displacement of the spring and v be the speed of the box.
when the box encounters the spring, all the energy of the box is kinetic energy:
the energy relationship between the box and the spring is given by:
1/2(m)×(v^2) = 1/2(k)×(x^2)
(m)×(v^2) = (k)×(x^2)
a) (m)×(v^2) = (k)×(x^2)
k = [(m)×(v^2)]/(x^2)
k = [(3)×((1.8)^2)]/((6.6×10^-2)^2)
k = 2231.40 N/m
Therefore, the force spring constant is 2231.40 N/m
b) (m)×(v^2) = (k)×(x^2)
v^2 = [(k)(x^2)]/m
v = \sqrt{ [(k)(x^2)]/m}
v = \sqrt{ [(2231.40)((1.8×10^-2)^2)]/(3)}
= 0.491 m/s
Answer:
f1 = -3.50 m
Explanation:
For a nearsighted person an object at infinity must be made to appear to be at his far point which is 3.50 m away. The image of an object at infinity must be formed on the same side of the lens as the object.
∴ v = -3.5 m
Using mirror formula,
i/f1 = 1/v + 1/u
Where f1 = focal length of the contact lens, v = image distance = -3.5 m, u = object distance = at infinity(∞) = 1/0
∴ 1/f1 = (1/-3.5) + 1/infinity
Note that, 1/infinity = 1/(1/0) = 0/1 =0.
∴ 1/f1 = 1/(-3.5) + 0
1/f1 = 1/(-3.5)
Solving the equation by finding the inverse of both side of the equation.
∴ f1 = -3.50 m
Therefore a converging lens of focal length f1 = -3.50 m
would be needed by the person to see an object at infinity clearly
Answer:C.The tube should be held vertically, perpendicular to the ground.
Explanation: Power lines are mainly overhead power installation that transfer electric energy from one place to another. Electric power lines contains both Magnetic field and Electric field.
Potential difference is the change in the amount of energy carried by an electric circuit from one point to another. TO MAXIMIZE THE POTENTIAL DIFFERENCE BETWEEN ONE END OF THE TUBE AND ANOTHER? THE TUBE SHOULD BE HELD VERTICALLY,PERPENDICULAR TO THE GROUND.
Answer:
Explanation:
Acceleration is the change in velocity with respect to time.
Acceleration = change in velocity/Time
Acceleration = final velocity - initial velocity/Time
Given initial velocity = 10m/s
Final velocity = 20m/s
Time taken = 4s
Acceleration = 20-10/4
Acceleration = 10/4
Acceleration =2.5m/s²
For the second part of the question:
Given parameters
initial velocity = 15m/s
acceleration = -3m/s²
time = 4seconds
a = v-u/t
-3 = v-15/4
cross multiply
-12 = v-15
add 15 from both sides
-12+15 = v-15+15
3 = v
<em>Hence the final velocity of the car is 3m/s</em>
