Embibe Experts Solutions for Exercise 3: Assignment

Two trains each of length $100 \mathrm{m}$ moving parallel towards each other at speed $72 \mathrm{km} {\mathrm{h}}^{-1}$ and $36 \mathrm{km} {\mathrm{h}}^{-1}$ respectively. In how much time will they cross each other?

A ball is dropped from the top of a building of height $80 \mathrm{m}.$ At same instant another ball is thrown upwards with speed $50 \mathrm{m} {\mathrm{s}}^{-1}$ from the bottom of the building. The time at which balls will meet is

A car travels with speed, $3 \mathrm{m}{ \mathrm{s}}^{-1}$ for the first half distance of the journey and with speed, $6 \mathrm{m}{ \mathrm{s}}^{-1}$ for the remaining half. What is the average speed of the entire journey?

A car travels from $A$ to $B$ at a speed of $40 \mathrm{km}{ \mathrm{h}}^{-1}$ and returns back on the same track at a speed of $60 \mathrm{km}{ \mathrm{h}}^{-1}.$ Average velocity will be

A particle starts from rest and accelerates constantly with $a \mathrm{m} {\mathrm{s}}^{-2}$ for $T$ second and then retards uniformly with the same rate till it comes to rest. The position-time $(x-t)$ graph of the particle is best represented by

An athlete completes one round of a circular track of radius $R$ in $20 \mathrm{s}$ with constant speed. What will be his displacement at the end of $1$ minute $10$ second?

The numerical ratio of displacement to the distance covered is always

A particle moves for $20 \mathrm{s}$ with speed $6 \mathrm{m} {\mathrm{s}}^{-1}$ and then speed $8 \mathrm{m} {\mathrm{s}}^{-1}$ for another $20 \mathrm{s}$ and finally moves with speed $10 \mathrm{m} {\mathrm{s}}^{-1}$ for next $20 \mathrm{s}.$ What is the average speed of the particle?