Answer:
11.28 N toward the center of the track
Explanation:
Centripetal force: This is the force that tend to draw a body close to the center of a circle, during circular motion.
The formula for centripetal force is given as,
F = mv²/r................................ Equation 1
Where F = force, m = mass of the toy car, v = velocity, r = radius
Given: m = 108 g = 0.108 kg, v = 7.75 m/s, r = 57.5 cm = 0.575 m
Substitute into equation 1
F = 0.108(7.75²)/0.575
F = 11.28 N
Hence the magnitude and direction of the force = 11.28 N toward the center of the track
Kinetic energy. thermal energy (a low form of energy ) is a form of kinetic energy as it is produced as a result of motion of particles either if they vibrate at their position or they move along longer paths. Motion produces friction or resistance which leads to excitation and thus the heat is produced. The higher the motion of the particles, the higher would be the thermal energy.
Answer:
B)velocity of object decreases
Explanation:
Consider the positive x axis as positive direction
Assume a body moving in negative x-axis direction
It's acceleration also alone negative x-axis direction
So according to our consideration
velocity and acceleration values are negative
That is both are towards negative x direction
But as both velocity and acceleration are in same direction, MAGNITUDE of velocity increases
But as magnitude increases in negative direction, velocity value decreases
But speed value increases(As speed is scalar and velocity is a vector)
The answer is C!! 100 kilometers per hour is an average speed.
Answer:
Explanation:
Given an RL circuit
A voltage source of.
V = 108V
A resistor of resistance
R = 1.1-kΩ = 1100 Ω
And inductor of inductance
L = 34 H
After he inductance has been fully charged, the switch is open and it connected to the resistor in their own circuit, so as to discharge the inductor
A. Time the inductor current will reduce to 12% of it's initial current
Let the initial charge current be Io
Then, final current is
I = 12% of Io
I = 0.12Io
I / Io = 0.12
The current in an inductor RL circuit is given as
I = Io ( 1—exp(-t/τ)
Where τ is time constant and it is given as
τ = L/R = 34/1100 = 0.03091A
So,
I = Io ( 1—exp(-t/τ))
I / Io = ( 1—exp(-t/τ))
Where I/Io = 0.12
0.12 = 1—exp(-t/τ)
0.12 — 1 = —exp(-t/τ)
-0.88 = -exp(-t/0.03091)
0.88 = exp(-t/0.03091)
Take In of both sides
In(0.88) = In(exp(-t/0.03091)
-0.12783 = -t/0.030901
t = -0.12783 × 0.030901
t = 3.95 × 10^-3 seconds
t = 3.95 ms
B. Energy stored in inductor is given as
U = ½Li²
So, the current at this time t = 3.95ms
I = Io ( 1—exp(-t/τ))
Where Io = V/R
Io = 108/1100 = 0.0982 A
Now,
I = Io ( 1—exp(-t/τ))
I = 0.0982(1 — exp(-3.95 × 10^-3 / 0.030901))
I = 0.0982(1—exp(-0.12783)
I = 0.0982 × 0.12
I = 0.01178
I = 11.78mA
Therefore,
U = ½Li²
U = ½ × 34 × 0.01178²
U = 2.36 × 10^-3 J
U = 2.36 mJ
