Question

A car is travelling at a speed of 90 km/h. Brakes are applied so as to produce a uniform acceleration of – 0.5 m/s2. Find how far the car will go before it is brought to rest?

Answer 1

Answer:

50 second

Explanation:

Speed of train , u = 90 km/h = 90 × 5/18 = 25 m/s

acceleration , a = -0.5 m/s²

Use formula,

v = u + at

Finally train will be rest so, final velocity, v = 0

0 = 25 - 0.5t

25 = 0.5t ⇒t = 50 sec

Again, use formula,

S = ut + 1/2at²

Where S is distance travelled before stop

S = 25 × 50 - 1/2 × 0.5 × 50²

= 1250 - 1/2 × 0.5 × 2500

= 1250 - 625

= 625 m

Hence, distance travelled = 625m and time taken = 50 sec

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Answer 2

Question -

A car is travelling at a speed of 90 km/h. Brakes are applied so as to produce a uniform acceleration of – 0.5 m/s2. Find how far the car will go before it is brought to rest?

Answer with explanation-

50 seconds

Speed of train, u = 90 km/h = 90 × 5/18 = 25 m/s

acceleration, a = -0.5 m/s²

Use formula,

V = u + at

Finally train will be rest so, final velocity, v = 0

0 = 25 - 0.5t

25 = 0.5t t = 50 sec

Again, use formula,

S = ut + 1/2at²

Where S is distance travelled before stop

S = 25 x 50 - 1/2 × 0.5 × 50²

= 1250 - 1/2 × 0.5 × 2500

= 1250 - 625

= 625 m

Hence, distance travelled = 625m and

time taken = 50 sec