P S Verma and V K Agarwal Solutions for Chapter: Model Test Paper 1, Exercise 1: SECTION-B

A body starting from rest travels with uniform acceleration. If it travels $100 \mathrm{m}$ in $5$ $\mathrm{s}$, what is the value of acceleration?

Explain by an example what is meant by potential energy. Write down the expression for the gravitational potential energy of a body of mass m placed at a height h above the surface of the earth.

What is the difference between potential energy and kinetic energy?

A ball of mass $0.5 \text{kg}$ slows down from a speed of $5 \raisebox{1ex}{$\text{ m}$}\!\left/ \!\raisebox{-1ex}{$\text{s}$}\right.$ to that of $3\raisebox{1ex}{$\text{ m}$}\!\left/ \!\raisebox{-1ex}{$\text{s}$}\right.$. Calculate the change in kinetic energy of the ball. State your answer giving proper units. 

 A boy of mass $50 \mathrm{kg}$ running at $5 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$ jumps onto a $20 \mathrm{kg}$ trolley travelling in the same direction at $1.5 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{s}$}\right.$. What is their common velocity?

A device called oscillator is used to send waves along a stretched string. The string is $20 \mathrm{cm}$ long, and four complete waves fit along its length when the oscillator vibrates $30$ times per second. For the waves on the string what is their wavelength?

A device called an oscillator is used to send waves along a stretched string. The string is $20 \mathrm{cm}$ long, and four complete waves fit along its length when the oscillator vibrates $30$ times per second. For the waves on the string, what is their frequency?
 

A device called an oscillator is used to send waves along a stretched string. The string is $20 \mathrm{cm}$ long, and four complete waves fit along its length when the oscillator vibrates $30$ times per second. For the waves on the string what is their speed?