Derive an expression for the time taken, (t) for a test mass to fall to the ground from a height (h) in a uniform gravitational field (g = 9.81 ms^-2)

We first build an intuition for exactly what acceleration is and what we expect to happen. In the uniform gravitational field approximation, we assume h to be much less than the radius of the Earth. Therefore, the higher we drop the test mass from, the larger the velocity of the test mass when it hits the ground at h = 0. Derivation: We take velocity = dh/dt = acceleration(g)*time(t), and then use the required calculus to integrate to find the expression: h = (1/2)gt^2 . We finally tidy this up by rearranging using basic algebra to express t as a function of h t(h) = SQRT(2h/g) (I would then very likely ask to plot that function so that the intuitions developed at the start can be solidified and we can gain some confidence in the use of calculus to solve real problems.) 

CB
Answered by Charlie B. Physics tutor

2213 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

What conditions are required for simple harmonic motion?


A 80kg man is hanging from two 1.5m ropes that lie at 60 degrees from the horizontal. What is the tension in each rope required to prevent the man from dropping?


In some SUVAT questions, they ask for 2 time solutions and I can only find 1. What am I missing?


How does the photoelectric effect (gold leaf experiment) demonstrate the particle nature of light?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning