Question

A car travels 80km in 8 hours. Find the speed of the car.

Answer 1

Given

$\tt Distance = 80 \: km$

$\tt Time = 8 \: hrs$

$\tt Speed = \dfrac{Distance}{Time}$

Thus,

$\tt Speed = \cancel{\dfrac{80 \: km}{8 \: hrs} }$

$\tt Speed = 10 \: km \: {h}^{ - 1}$

Thus, the speed of car is 10 km/h

Additional Information

• Speed is rate at which a body travels in respect to time.

• Speed is a Vector Quantity

• Distance is always greater than Displacement or equal

• Unit is a standard Quantity of though which different quantities can be compared

Eg:-

1. Mass → Kilogram (kg)
2. Length → metre (m)
3. Time → second (s)
4. Temperature → kelvin(K)
5. Current → Ampere(A)
6. Force → Newton(N)

Some Important Formulas

• $\sf Speed = \dfrac{Distance}{Time}$

• $\sf Area = Length \times Breadth$

• $\sf Acceleration = \dfrac{Velocity}{Time}$

• $\sf Density = \dfrac{Mass}{Volume}$

• $\sf Volume = Length \times Breadth \times Height$

• $\sf v = u + at$

• $\sf v^{2} -u^{2} = 2aS$

• $\sf S = ut + \dfrac{1}{2} at ^{2}$

Answer 2

${\underline {\underline{{\red{ \rm Given }}}}}$

• $\purple{ \sf Distance \rightarrow 80 \: km}$
• $\purple{\sf Time \rightarrow 8 \: hrs}$

$\underline {\underline{{ \red{\rm To \: Find }}}}$

• Speed of the Car

Formula Used :- $\underline{\underline{\boxed{ \pink{\sf Speed = \dfrac{Distance}{Time} }}}}$

Substituting Values

$\blue {\bf \longrightarrow \cancel{\dfrac{80}{8}}}$

$\blue {\bf \longrightarrow 10 }$

${\green{ \underbrace{\boxed{\underline{\underline{\purple{ \tt Thus, the \: speed \: of \: car \: is \: 10 \: km/hr }}}}}}}$

${\pink{ \underbrace{\boxed{\underline{\underline{\red{ \sf Equations \: of \: Motion }}}}}}}$

• v = u + at
• S = ut + ½ at²
• v² - u² = 2as

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