Answer:
Its acceleration is positive
Explanation:
As the car is moving in the negative x-direction than after applying brake then there will be a decrease in the acceleration but in the opposite direction.
As decreasing acceleration consider to be negative but the car is moving in negative direction which means increasing acceleration is negative by sign convention but by applying brake acceleration decrease but in opposite direction than it will give positive value of acceleration.
Answer:
Explanation:
a ) Earlier emf of cell applied on R₁ but now emf will be distributed among R₁ and R₂
Potential difference on R₁ will become less .
b ) Current is inversely proportional to resistance of the circuit. As resistance increases , current will be less . So current through R₁ will become less.
c )
When resistance is added in series , they are added up to obtain equivalent resistance . So equivalent resistance R₁₂ will be more than R₁ OR R₂.
Answer:
Pi(3.14) radians or 180º degrees
Explanation:
First of all, we need to obtain the wavelength of a wave traveling to the speed of sound and 420 Hz of frequency.
The formula is:

where l = wavelength in meters
With current values:
l = 336 [m/s]/420[1/s] = 0.8 meters
Since a complete cycle (360º or 2pi radians) needs 0.8 meters to complete, 0.4 meters or 40 cm is just half of it, making a 180º degree phase or 3.14 radians.