I dont know why my answers are wrong or what the correct answer would be

Q1:

Atourist being chased by an angry bear is running in a straight line toward his car at a speed of 3.06 m/s. The car is a distance d away. The bear is 16.5 m behind the tourist and running at 3.92 m/s. The tourist reaches the car safely. What is the maximum possible value for d? "bear \"tourist '. '. Number i 792 Units E] A motorcycle has a constant acceleration of 2.25 m/sz. Both the velocity and acceleration of the motorcycle point in the same direction. How much time is required for the motorcycle to change its speed from (a)27.8 to 37.8 m/s, and (b)57.8 to 67.8 m/s? (a) Number i Units {:1 [:9 II II.)- (b) Number i Before starting this problem, review Multiple-Concept Example 6. The left ventricle of the heart accelerates blood from rest to a velocity of +21.9 cm/s. (a) If the displacement of the blood during the acceleration is +2.82 cm, determine its acceleration (in cm/$2). (b) How much time does blood take to reach its final velocity? (a) Number i 7.8 Units cm/s^2 4 (b) Number 3.8 Units SSuppose a car is traveling at +23.0 m/s, and the driver sees a traffic light turn red. After 0.397 s has elapsed (the reaction time), the driver applies the brakes, and the car decelerates at 9.00 m/s2. What is the stopping distance of the car, as measured from the point where the driver first notices the red light? Number i 91.3 Units m