Answer: 4 hours
Explanation: Their approach rate is 100+140 or 240 km/h and 960/240 which equals 4 hours
Explanation:
(a) We know that the acceleration of the car is given by :
a = change in speed / time taken
If the speed of the car is constant in a straight line, the acceleration of the car is zero because there is no change in the speed of the car.
(b) For the driver steer a car traveling at constant speed so that the magnitude of the acceleration remains constant, the driver should drive the car in the circular path. This is because, in circular path the speed of an object remains the same while its velocity changes.
When air resistance acts, acceleration during a fall will be less than g because air resistance affects the motion of the falling objects by slowing it down. ... Air resistance depends on two important factors - the speed of the object and its surface area.
Answer: A.The total number of energy levels the electron can jump to.
Explanation:
Spectral lines are bright or dark lines over continuous spectrum which occur due to emission or absorption of energy.
When an electron jumps to or from one energy level to another energy level, spectral lines are produced. The range of spectral lines depends on the number of energy levels available to which the electron can jump. This depends the amount of energy gained/lost by the electron.
Thus, the correct answer is: A.The total number of energy levels the electron can jump to.
Answer:
Yes, the race car driver needs a faster reaction time than someone driving in a school zone.
Explanation.
For the sake of argument, let us consider
(i) a person driving at 35 mph in a school zone (as a normal driver);
(ii) a person driving at 60 mph in a school zone (as a racing driver).
Suppose a blind pedestrian crosses the road 0.1 miles (about 500 feet) in front of the driver.
The time before the normal driver hits the pedestrian is
(0.1 /35)*3600 = 10.3 seconds.
The time before the racing driver hits the pedestrian is
(0.1/60)*3600 = 6 seconds.
Because a reaction time of 6 seconds may be insufficient to avoid hitting the pedestrian, the racing driver needs a faster reaction time than the normal driver.
