Answer:
in t seconds, Car A sweep out t radian { i.e θ = t radian }
Explanation:
Given the data in the question;
4 toy racecars are racing along a circular race track.
They all start at 3 o'clock position and moved CCW
Car A is constantly 2 feet from the center of the race track and moves at a constant speed
so maximum distance from the center = 2 ft
The angle Car A sweeps out increases at a constant rate of 1 radian per second.
Rate of change of angle = dθ/dt = 1
Now,
since dθ/dt = 1
Hence θ = t + C
where C is the constant of integration
so at t = 0, θ = 0, the value of C will be 0.
Hence, θ = t radian
Therefore, in t seconds, Car A sweep out t radian { i.e θ = t radian }
The wavelength would decrease because frequency is inversly proportional to the wavelength provided the speed is constant: f=v/λ
Answer: The correct option is A.
Explanation:
Inertia is a state of an object or body to maintain its state. It resists any change in its state.
Newton's first law of inertia: When an objects is in state of motion, it will remain its state of motion or if it is in state of rest then it will remain in rest unless it is acted upon by external motion.
In the given options, a ball sits motionless on the ground is good example of Newton's first law motion. No external force is acting in this case.
In options (B), (C) and (D) , the external force is acting.
Therefore, the correct option is A.
