Application of Negative Numbers in Speed Distance Time

Q.

If a body covers a distance x with speed v₁ and then it covers another distance x with speed v₂, find the average speed for the whole journey.

Q. An athlete runs up 10 steps before his long jump. If he starts 3 steps before the starting line, his run up would end at steps from the line.

1. 4
2. 2
3. -6
4. -4
5. 13

Q. A car is moving with constant speed of
$v$ = 40 $km/h$. What distance will be covered by the car in $1\frac{1}{2}$ hours?

1. 60 km
2. 50 km
3. 80 km
4. 70 km

Q. An object is thrown straight up at the speed of 49 metres per second. is the equation to find the speed of the object at every second.

1. $v=49+9.8t$
   
2. $v=49-9.8t$
3. $v=9.8-49t$
4. $v=9.8+49t$

Q.

Write down the units and dimensional formulae of following physical quantities:
Speed

Q. A bike is moving with velocity $v$ and time$t$, data as shown on the following table.Here negative time means time before the starting of observation.
Choose the correct option(s).

1. Distance covered at time -2$s$ is 12$m$
2. Distance covered at time 4$s$ is 40$m$
3. Distance covered at time -2$s$ is -12$m$
4. Distance covered at time 0$s$ is 0$m$

Q.

A man walked 5 km towards North then 8 km towards South. What is his final position with respect to his initial position?

1. 4 units

2. -4 units

3. -3 units

4. 1 unit

Q. A man walked 3 km towards North then 8 km towards South. What is his final position with respect to his initial position?

1. 5 km towards East
2. 3 km towards South
3. 8 km towards North
4. 5 km towards South

Q.

A man walked 3 km towards North then 8 km towards South. What is his final position with respect to his initial position?

1. 3 km towards South

2. 8 km towards North

3. 5 km towards South

4. 5 km towards East

Q. The fuel consumption of an engine is $\frac{1}{6,000}\times \left(\right(Speed{)}^3\times Time)$ L. If a distance of 120 km has to be covered in exactly 4 h, what should be the minimum amount of fuel at the start of the journey so that the driver can make it? [Speed is in km/h and time is in h.]

1. 18

Q. Velocity is defined as$v=u+5t$, where$u$ is fixed- $5m{s}^{-1}$. Find$v$ at different$t$.

1. $v=5m{s}^{-1}$
2. $v=10m{s}^{-1}$
3. $v=15m{s}^{-1}$
4. $v=20m{s}^{-1}$

Q.

A man walked 3 km towards North then 8 km towards South. What is his final position with respect to his initial position?

1. 5 km towards East

2. 3 km towards South

3. 8 km towards North

4. 5 km towards South

Q.

A train of 150 m in length is going in the north direction at a speed of 10 $\frac{m}{s}$.A parrot flies at a speed of 5$\frac{m}{s}$towards the south direction parallel to the railway track. The time taken by the parrot to cross the train is equal to. In the above questions, if the parrot flies at a speed of 5$\frac{m}{s}$ towards the north. The time taken by the train to leave past the parrot is :

1. 25 s

2. 20 s

3. 30 s

4. 50 s

Q. The fuel consumption of an engine is $\frac{1}{6,000}\times \left(\right(Speed{)}^3\times Time)$ L. If a distance of 120 km has to be covered in exactly 4 h, what should be the minimum amount of fuel at the start of the journey so that the driver can make it? [Speed is in km/h and time is in h.]

1. 18

Q.

Prashanthi travels 30 km towards North then takes about turn and then travels south for 55 km. Taking North direction as positive and south direction as negative, find the prashanthi's distance from the initial starting point.

1. 65 km towards the south.

2. 25 km towards the south.

3. 25 km towards the north.

4. 50 km towards the south.

Q.

An elevator descends into a mine shaft at the rate of 15m/min. If the descend starts from 10 m above the ground level, how long will it take to reach -140m.

1. 18 minutes

2. 38 minutes

3. 10 minutes

4. 8 minutes