B. I think is the correct answer
Answer:
Explanation:
This is a uniformly accelerated motion, so we can determine the deceleration of the car by using a suvat equation:
where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance covered
For the car in this problem,
u = 27.8 m/s
v = 0
s = 17 m
Solving for a, we find the acceleration:
Answer:
the angular velocity of the carousel after the child has started running =
Explanation:
Given that
the mass of the child = m
The radius of the disc = R
moment of inertia I =
change in time =
By using the torque around the inertia ; we have:
T = I×∝
where
R×F = I × ∝
R×F = ∝
F = ∝
∝ = ( expression for angular angular acceleration)
The first equation of motion of rotating wheel can be expressed as :
where ;
∝ =
Then;
∴ the angular velocity of the carousel after the child has started running =
The photon can be absorbed and the energy of the photon is exactly equal to the energy-level difference between the ground state and the level d.
Answer:
The instantaneous velocity is the specific rate of change of position (or displacement) with respect to time at a single point (x,t) , while average velocity is the average rate of change of position (or displacement) with respect to time over an interval.Average velocity : Average velocity of a body is defined as the change in position or displacement (Δx) divided by time interval (Δt) in which that displacement occurs.
Instantaneous velocity : The instantaneous velocity of a body is the velocity of the body at any instant of time or at any point of its path .
velocity can be positive , negative or zero.
By studying speed and velocity we come to the result that at any time interval average speed of an object is equal or more than the average but instantaneous speed is equal to instantaneous velocity.