Home › CBSE Class 11 (Science) › Physics › Motion in a Straight Line › A ruler dropped through your fingers is caught a…
A ruler dropped through your fingers is caught after falling 21.0 cm. Roughly what is the reaction time?
A2.1 s
B0.42 s
C0.21 s
D0.021 s
Answer & Solution
Correct answer: C. 0.21 s
t = sqrt(2d/g) = sqrt(0.42/9.8) is about 0.21 s.
Related questions
Which kind of motion did Domingo de Soto in 1545 correctly identify with uniformly accelerA cyclist moving at 10 m/s accelerates uniformly at 2 m/s^2 for 4 s. What is the final speHow many of the five SUVAT variables does each constant-acceleration equation of motion coA scooter starts from rest and reaches 20 m/s with a uniform acceleration of 5 m/s^2. WhatA train speeds up uniformly from 10 m/s to 30 m/s in 10 s. What is its acceleration?A bike moving at 20 m/s brakes with a uniform retardation of 4 m/s^2. How long does it takA car starts from rest and accelerates uniformly at 2 m/s^2 along a straight road. How farA body moves with constant velocity. Its acceleration is