All Problems

Kinematics

Problem 1.19

A point traversed half a circle of radius R=160 cmR=160 \mathrm{~cm} during time interval τ=10.0\tau=10.0 s. Calculate the following quantities averaged over that time: (a) the mean velocity v\langle v\rangle; (b) the modulus of the mean velocity vector v|\langle\mathbf{v}\rangle| (c) the modulus of the mean vector of the total acceleration w|\langle\mathbf{w}\rangle| if the point moved with constant tangent acceleration.

Reveal Answer
 (a) v=πR/τ=50 cm/s (b) v=2R/τ=32 cm/s (c) w=2πR/τ2=10 cm/s2\text { (a) }\langle v\rangle=\pi R / \tau=50 \mathrm{~cm} / \mathrm{s} \text { (b) }|\langle\mathbf{v}\rangle|=2 R / \tau=32 \mathrm{~cm} / \mathrm{s} \text { (c) }|\langle\mathbf{w}\rangle|=2 \pi R / \tau^{2}=10 \mathrm{~cm} / \mathrm{s}^{2}