Question

Question 3.3:
A woman starts from her home at 9.00 am, walks with a speed of 5 km h–1 on a straight
road up to her office 2.5 km away, stays at the office up to 5.00 pm, and returns home by
an auto with a speed of 25 km h–1

. Choose suitable scales and plot the x-t graph of her

motion.

Answer 1

Answer:

Answer 3.3: [ncert11 motion in straight line]

Speed of the woman = 5 km/h

Distance between her office and home = 2.5 km

It is given that she covers the same distance in the evening by an auto.

Now, speed of the auto = 25 km/h

The suitable x-t graph of the motion of the woman is shown in the given figure.

Answer 2

Required solution :-

Given that,

Speed of the lady = 5 km/h

Distance from her home and to her office = 2.5 km

Speed of the bus = 25 kmph

We know that,

• s = Speed
• d = Distance
• t = Time

By the formula,

$\underline{\boxed{\sf Time \ taken =\dfrac{Distance}{Speed} }}$

Given that,

Speed (s) = 5 km/h

Distance (d) = 2.5 km

Substituting their values,

t = 2.5/ 5

t = 0.5 h = 30 min

She covers the same distance in the evening on a bus as she returns home.

Given that,

Speed of the bus (s) = 25 kmph

Time taken = Distance/ Speed

By substituting,

t = 2.5/25

t = 0.1 h = 6 min