Engineering Board Exam Reviewer · Engineering Mechanics · medium
An object is dropped from rest from a height of 23 m. Neglecting air resistance, how long does it take to hit the ground? (g = 9.81 m/s2)
- 2.34
- 1.53
- 2.17
- 4.33
Answer
C. 2.17
Solution
Using h = 1/2gt2: t = sqrt(2h/g) = sqrt(2(23)/9.81) = 2.17 s.
More Engineering Mechanics questions
- A particle starts with an initial velocity of 5 m/s and a constant acceleration of 2 m/s2. What distance does it travel in 5 seconds?
- A car starts with an initial velocity of 6 m/s and accelerates uniformly at 3 m/s2 for 4 seconds. What is its final velocity?
- A projectile is launched with an initial speed of 20 m/s at an angle of 25° above the horizontal. Neglecting air resistance, what is its…
- An object is dropped from rest from a height of 20 m. Neglecting air resistance, how long does it take to hit the ground? (g = 9.81 m/s2)
- A particle starts with an initial velocity of 4 m/s and a constant acceleration of 1.5 m/s2. What distance does it travel in 4 seconds?
- A car starts with an initial velocity of 5 m/s and accelerates uniformly at 2 m/s2 for 3 seconds. What is its final velocity?
- A reference frame in which Newton's laws of motion hold true without correction is called a(n):
- In dynamics, D'Alembert's principle allows a dynamic problem to be treated as a static equilibrium problem by introducing:
- According to Newton's first law (law of inertia), a body at rest or in uniform motion will remain so unless:
- Kinematics differs from kinetics in that kinematics: