Jan Dangerfield, Stuart Haring and, Julian Gilbey Solutions for Exercise 2: EXERCISE 2A

Find the constant force required to accelerate a mass of $5 \mathrm{kg}$ from $3{ \mathrm{ms}}^{-1}$ to $7 \mathrm{m}{ \mathrm{s}}^{-1}$ in $8 \mathrm{s}$ on a horizontal surface.

A ship of mass $20$ tonnes is moving at $10 \mathrm{m}{ \mathrm{s}}^{-1}$ when its engines stop and it decelerates in the water. It takes $500 \mathrm{m}$ to come to rest. Find the resistance force, which is assumed to be constant, of the water on the ship.

A winch provides a constant force of $80 \mathrm{N}$ and causes a block to accelerate on horizontal land from $2 \mathrm{m}{ \mathrm{s}}^{-1}$ to $10 \mathrm{m}{ \mathrm{s}}^{-1}$ in $6 \mathrm{s}.$ Find the mass of the block.

A Formula $1$ car and its driver have total mass of $800 \mathrm{kg}.$ The driver is travelling at $100 \mathrm{m}{ \mathrm{s}}^{-1}$ along a horizontal straight when, $100 \mathrm{m}$ before a bend, he starts to brake, slowing to $40 \mathrm{m}{ \mathrm{s}}^{-1}.$ Assuming a constant braking force, find the force of the brakes on the car.

A strongman drags a stone ball from rest along a horizontal surface. He moves it $10 \mathrm{m}$ in $4 \mathrm{s}$ by exerting a constant force of $100 \mathrm{N}.$ Find the mass of the stone ball.

A car and driver, of total mass $1350 \mathrm{kg},$ are moving at $30{ \mathrm{ms}}^{-1}$ on a horizontal road when the driver sees roadworks $400 \mathrm{m}$ ahead. She brakes, decelerating with a constant force of $600 \mathrm{N}$ until arriving at the roadworks. Find the time elapsed before arriving at the roadworks.

A train travelling at $30 \mathrm{m}{ \mathrm{s}}^{-1}$ on a horizontal track starts decelerating $360 \mathrm{m}$ before coming to rest at a platform. The brakes provide a constant resistance of $100 \mathrm{kN}.$ Find the mass of the train.

A block is being dragged along a horizontal surface by a constant horizontal force of size $45 \mathrm{N}.$ It covers $8 \mathrm{m}$ in the first $2 \mathrm{s}$ and $8.5 \mathrm{m}$ in the next $1 \mathrm{s}.$ Find the mass of the block.