Q5) A car moving at 20 m/s is 30 meters away from a wall when the driver applies the brakes and manages to stop safely before reaching the wall.
a) Find the acceleration of the car?
b) Calculate the time required to stop the car.
Q6) A moving race car has a mass of 1200 kg decelerate due to friction at 30 m/s² and it stopped completely after 2 s.
Calculate a) The initial velocity of this car?
b) The total distance that it moves before stopping?
c) The magnitude of the friction force acting on it.
Q7) A neural impulse travels along an axon with an initial velocity of 10 m/s. As it passes through a myelinated region, it accelerates at a constant rate of 15 m/s² for 10 ms before reaching a constant velocity again.
Calculate: a) The final velocity of the impulse after acceleration?
b) The distance traveled during the acceleration phase?
c) The time required for the impulse to travel 10 cm after the acceleration phase?
Q8) A medical centrifuge used to separate blood components rotates at 3600 RPM. The test tubes are placed in holders 15 cm from the axis of rotation.
a) Calculate the velocity in m/s ?
b) Calculate the centripetal acceleration experienced on the blood samples?
c) Determine the centripetal force on a red blood cell with mass 27 × 10⁻¹² kg?
Q9) A rehabilitation patient starts walking from rest with a constant acceleration of 0.25 m/s².
Calculate: a) The time required to reach a walking speed of 1.5 m/s?
b) The distance covered during this time?
and c) The average velocity during this time period?
Q10) A 2.5 kg object initially at rest is subjected to a constant force of 15 N for 4 seconds.
Calculate:
a) the acceleration of the object?
b) the final velocity of the object? ,
and c) the distance traveled during this time?
Q11) A 1500 kg car accelerates from rest to 25 m/s in 10 seconds on a horizontal road.
Calculate: a) The net force acting on the car?
b) A passenger of mass 70 kg sits in the car?
Calculate b1) the normal force exerted by the seat on the passenger and
b2) the force exerted by the passenger on the seat?
d) If the car suddenly applies brakes providing a deceleration of 8 m/s², calculate the force experienced by the passenger?
