Question

a car of mass 1000kg accelerates from 18 km / h to 36 km/ h in 5 s. find (a) acceleration (b) distance covered by car (c) force​

Answer 1

Given :-

• Mass of car = 1000 kg.
• Initial velocity (u) = 18 km/h.
• Final velocity (v) = 36 km/h.
• Time taken = 5s.

Need to find :-

• Acceleration ?
• Distance covered ?
• Force ?

Solution :-

• first, we'll find acceleration.

• we know that, 1 km = 1000 m & 1 hr = 60 min.

Initial velocity (u) = ${ \sf{ \frac{18 \times 1000} {60 \times 60} = \frac{18000}{3600} = 5m /s}}$

Final velocity (v) = ${ \sf{ \frac{36 \times 1000} {60 \times 60} = \frac{36000}{3600} = 10m /s}}$

Formula Used :-

${ \boxed{ \sf{Acceleration = \frac{(v - u)}{t}}} }$

Substituting the given values in the above equation: we get,

${ \sf{Acceleration = \frac{10 - 5}{5} }}$

${ \sf{Acceleration = \frac{5}{5} }}$

${ \sf{ \underline{Acceleration =1m/s}}}$

• Now, we'll find distance covered by car.

• Formula Used :-

${ \boxed{ \sf{Distance = \: ut + \frac{1}{2} at ^{2} }}}$

Substituting the given values in the above equation: we get,

${ \sf{Distance =5 \times 5 + \frac{1}{2} \times 1 \times 5 ^{2} }}$

${ \sf{Distance =25 + \frac{1}{2} \times \: 25}}$

${ \sf{Distance =25 + 12.5}}$

$\underline{ \sf {Distance =37.5m}}$

• Now, we'll find force.

• Formula Used :-

$\boxed{ \sf{Force = \: mass \times acceleration}}$

Substituting the given values in the above equation: we get,

${ \sf{Force = \: 1000 \times 1}}$

${ \underline{ \sf{Force = \: 1000 \: N}}}$

________________________