Exams & Certification
You are driving in a car at 15 m/s, approaching an intersection that is 8.0 meters long. When you are 35 m away from the beginning of the intersection, the light turns yellow – it will turn red in 2.0 seconds. You must decide if you will hit the gas or the brakes. By hitting […]
You are driving in a car at 15 m/s, approaching an intersection that is 8.0 meters long Read More »
A skier covers the final 110 meters of a race in 5.0 seconds, crossing the finish line at a speed of 24 m/s. What was her (constant) acceleration? The correct answer and explanation is : Answer: The skier’s constant acceleration is 0.8 m/s². Explanation: To determine the acceleration of the skier, we use the kinematic
You are driving in a car at 15 m/s, approaching an intersection that is 8.0 meters long. When you are 35 m away from the beginning of the intersection, the light turns yellow – it will turn red in 2.0 seconds. You must decide if you will hit the gas or the brakes. By hitting
You are driving in a car at 15 m/s, approaching an intersection that is 8.0 meters long Read More »
A car starts from rest and accelerates at a constant 1.5 m/s2. Some time later, it takes 2.1 s to cross over a 25-meter long bridge. How far did the car travel before getting onto the bridge? The correct answer and explanation is : The car traveled approximately 35.57 meters before reaching the bridge. Explanation:
A car starts from rest and accelerates at a constant 1.5 m/s2 Read More »
From the edge of a cliff, a gun fires a pellet straight upward. The pellet’s speed after leaving the gun is 30 m/s; the cliff is 75 meters tall. Assume that the ground is at height = 0 and that the positive direction is upward. At what time does the pellet hit the ground? The
From the edge of a cliff, a gun fires a pellet straight upward Read More »
A stone is dropped from the roof of a high building. A second stone is dropped 1.50 s later. How far apart are the stones when the second one has reached a speed of 12.0 m/s? The correct answer and explanation is : To solve this problem, we analyze the motion of both stones using
A stone is dropped from the roof of a high building Read More »
A police officer is called in for accident reconstruction. He measures 11-meter long skid marks and he knows that for that particular tire/pavement combination, the coefficient of kinetic friction is 0.65. He also knows that the car was traveling at 3.5 m/s just before impact (the end of the skid marks). What was the speed
A police officer is called in for accident reconstruction Read More »
The complex [Ni(CN)4]The complex [Ni(CN)4]2- is diamagnetic but [NiCl4]2- is paramagnetic (both d8), with two unpaired electrons. Similarly, [Fe(CN)6]3- has only one unpaired electron, but [Fe(OH2)6]3+ has 5. Explain these experimental observations using: a) the Valencia Bond Theory. b) the Crystalline Field Theory. The correct answer and explanation is : Explanation of Magnetic Properties Using
The complex [Ni(CN)4] Read More »
The coefficient of kinetic friction between a particular car’s tires and the ground is 0.60. The coefficient of static friction is 0.75.Given the above information and the assumption that friction is the limiting factor, not the car’s engine, determine the maximum acceleration of the car. Use this to determine the time to accelerate from zero
fraction numerator 3.5 over denominator x end fraction equals fraction numerator 4.5 over denominator y end fraction explain the problem with given data and calculate the fraction respectively The correct answer and explanation is : To solve the proportion ( \frac{3.5}{x} = \frac{4.5}{y} ) for the variables ( x ) and ( y ), we