Question

A vehicle is accelerating uniformly at 1.8ms -2 from speed of 30km/h. What’s the time required to attain a speed of 90 km/h?

Answer 1

To find the time required for the vehicle to attain a speed of 90 km/h, we can use the equation of motion for uniformly accelerated motion:

$v=u+at$

Where:

• $v$ is the final velocity (90 km/h)
• $u$ is the initial velocity (30 km/h)
• $a$ is the acceleration (1.8 m/s${}^2$)
• $t$ is the time taken

First, let's convert the velocities from km/h to m/s:

Initial velocity, $u=30\text{km/h}\times \left(\frac{1000\text{m}}{1\text{km}}\right)\times \left(\frac{1\text{h}}{3600\text{s}}\right)=8.33\text{m/s}$

Final velocity, $v=90\text{km/h}\times (\frac{1000}{1\text{km}}$