Equations of motion and Free Fall

A jet plane lands with a speed of 80 m/s and decelerates at a rate of 20 m/s² as it comes to rest. From the instant the plane touches the runway, what is the minimum time needed before it can come to rest?

• 2 s

• 3 s

• 4 s

• 5 s

A student drops a ball from a window 3.5 𝑚 above the sidewalk. How fast is it moving when it hits the sidewalk?

• 1.5 m/s

• 2.4 m/s

• 5.6 m/s

• 8.3 m/s

An object is thrown straight up with an initial speed of 20 𝑚/𝑠 from the top of a 105 𝑚 high building. Calculate the maximum height (as measured from the ground) the object reaches.

• 15 m

• 200 m

• 125 m

• 170 m

An object is thrown straight up with an initial speed of 20 𝑚/𝑠. Calculate the time it takes to reach the maximum height.

• 2 s

• 6 s

• 1.3 s

• 3.2 s

Which of the following correctly describes the motion represented by the velocity-time graph shown below?

• Speeds up with a variable positive acceleration

• Slows down with a constant positive acceleration

• Speeds up, stops and then slows down with a variable negative acceleration

• Slows down, stops and then speeds up with a constant negative acceleration

A motorcycle, initially moving with a speed of 4.0 m/s, speeds up at a constant rate to 6.0 m/s after covering a distance of 5.0 m. What is the acceleration of the motorcycle?

• 3 m/s²

• 2 m/s²

• 6 m/s²

• 5 m/s²

A bullet that is shot straight up returns to its starting point in 10.0 s. What is the initial speed of the bullet?

• 50 m/s

• 38 m/s

• 27 m/s

• 14 m/s

Consider the position-time graph below for an object projected upwards and experiencing free fall. Which of the following is true about point D?

• Ball is moving up with + acceleration

• Ball is moving down with - acceleration

• Ball is moving up with - acceleration

• Ball is moving down with + acceleration

Consider the position-time graph below for an object projected upwards and experiencing free fall. Which of the following is the correct ranking for the speed of the object at positions A, C and D?

• V_A < V_c < V_D

• V_A < V_D < V_C

• V_c < V_A < V_D

• V_D < V_A < V_C

In a race, a runner traveled 16 meters in 3.0 seconds as she accelerated uniformly from rest. The magnitude of the acceleration of the runner was ______.

• 0.25 m/s²

• 3.5 m/s²

• 5.0 m/s²

• 2.4 m/s²