Answer:
Zero
Explanation:
The acceleration of body moving with uniform velocity is zero, because there is no change in velocity.
Answer:
n = 1.42
Explanation:
The refractive index for a medium is given by the ratio of the speed of light in vacuum to the speed of light in a medium.

So, the refractive index of the medium is 1.42.
Answer:
3.76 m/s
Explanation:
Instantaneous velocity: This can be defined as the velocity of an object in a non uniform motion. The S.I unit is m/s.
v' = dx(t)/dt..................... Equation 1
Where v' = instantaneous velocity, x = distance, t = time.
Given the expression,
x(t) = 28.0 m + (12.4 m/s)t - (0.0450 m/s³)t³
x(t) = 28 + 12.4t - 0.0450t³
Differentiating x(t) with respect to t.
dx(t)/dt = 12.4 - 0.135t²
dx(t)/dt = 12.4 - 0.135t²
When t = 8.00 s.
dx(t)/dt = 12.4 - 0.135(8)²
dx(t)/dt = 12.4 - 8.64
dx(t)/dt = 3.76 m/s.
Therefore,
v' = 3.76 m/s.
Hence, the instantaneous velocity = 3.76 m/s
Answer:
163.35
__________________________________________________________
<u>We are given:</u>
Mass of the object (m) = 36.3 kg
Velocity of the object (v) = 3 m/s
<u>Kinetic Energy of the object:</u>
We know that:
Kinetic Energy = 1/2(mv²)
KE = 1/2(36.3)(3)² [replacing the variables with the given values]
KE = 18.15 * 9
KE = 163.35 Joules
Hence, the cart has a Kinetic Energy of 163.35 Joules