Question

5. A racing car travels 425 m in 10 sec; express this speed in km per hour.
6. A flask weighs 64.27 g when empty and 150.35 g when full of water. Find its weight when it is half full of
water.
nide in common Ifa side of the triangle is 15 mm long,​

Answer 1

Question :-

A racing car travels 425 meters in 10 seconds . Find the speed of the car . Express the speed in kilometres per hour ?

Answer :-

Given :-

A racing car travels 425 meters in 10 seconds

Required to find :-

• Speed of the car in km/hr

Formula used :-

$\large{\leadsto{\boxed{\rm{ Speed = \dfrac{Distance}{Time}}}}}$

Solution :-

Given :-

A racing car travels 425 meters in 10 seconds

He asked us to find the speed of the car in km/hr

So,

Distance travelled by the racing car = 425 meters

Time taken = 10 seconds

Using the formula,

$\large{\leadsto{\boxed{\rm{ Speed = \dfrac{Distance}{Time}}}}}$

So,

$\longrightarrow{\tt{ Speed = \dfrac{ 425 \; m }{ 10 \; seconds }}}$

$\longrightarrow{\tt{ Speed = 42.5 m/s }}$

Now we have to convert this m/s into km/hr .

So,

$\tt{ 1\;m/s = \dfrac{18}{5}km/hr}$

$\tt{ 42.5 \times \dfrac{18}{5}}$

$\tt{ 8.5 \times 18 }$

$\implies{\tt{ 153 \; km/hr }}$

$\large{\leadsto{\boxed{\therefore{Speed = 153 \; km/hr }}}}$

$\rule{400}{10}$

Question :-

A flask weights 64.27 grams when empty and 150.35 grams when full of water . Find its weight when it is filled water to its halved .

Answer :-

Given :-

Weight of the empty flask = 64.27 grams

Weight of the flask when filled completely in water = 150.35 grams

Required to find :-

• Weight of the flask when filled with half of the water ?

Solution :-

Given that,

Weight of the empty flask = 64.27 grams

Weight of the flask when filled completely in water = 150.35 grams

He asked us to find ,

Weight of the flask when filled with water to its half

So,

First we need to find the weight of the water in the completely with water .

Hence,

In order to find it ,

We should subtract the weight of the flask when completely filled with water with weight of the empty flask .

So,

Weight of the water = 150.35 - 64.27

Weight of the water = 86.08 grams

Similarly,

Now divide the weight of the water by 2 to find the weight of the half water .

So,

86.08 /2

= 43.04 grams

Hence,

Weight of the flask when filled with water to its half = weight of the half water + weight of the empty flask

$\implies{\tt{ 64.27 + 43.04 }}$

$\implies{\tt{ 107.31\;grams }}$

$\large{\leadsto{\boxed{\rm{Weight \; of \; flask \; when \; filled \; by \; it's\; half = 107.31 grams }}}}$

$\rule{400}{10}$