Speed

Q. A train travels with a speed of $60$ km/h from station A to station B and then comes back with a speed $80$ km/h from station B to station A. Find the average speed of train.

Q.

The height $‘h’$ at which the weight of a body will be the same as that at the same depth $‘h’$ from the surface of the earth is (Radius of the earth is $R$ and effect of the rotation of the earth is neglected):

1. $\frac{\sqrt{3R}-R}{2}$

2. $\frac{\sqrt{5}}{2}R-R$

3. $\frac{\sqrt{5}R-R}{2}$

4. $\frac{R}{2}$

Q.

The height at which the weight of a body becomes $\frac{1}{16}th$ its weight on the surface of (radius$R$) is

1. $3R$

2. $4R$

3. $5R$

4. $15R$

Q.

what is velocity

Q.

A car covers the first 30 km in 30 min and the next 30 km in 40 min. Calculate the average speed for the entire journey.

1. $51.2km/h$

2. $55.5km/h$

3. $51.4km/h$

4. $52.4km/h$

Q.

A van covers 30km with a uniform speed of 60 km/h and the next 30km with a uniform speed of 40km/h. Find the total time taken and the average speed.

1. 60 minutes, 30 km/h

2. 75 minutes, 35 km/h

3. 70 minutes, 20 km/h

4. 75 minutes, 48 km/h

Q.

Choose the correct option:

1. distance is a scalar, velocity is a vector , acceleration is a vector.

2. distance is a vector, velocity is a vector, acceleration is a vector.

3. distance is a scalar, velocity is a vector, acceleration is a scalar.

4. distance is a vector, velocity is a scalar, acceleration is a vector.

Q.

A Quantity which has both magnitude and direction is called.

1. Distance

2. Moving body

3. Scalar quantity

4. Vector quantity

Q. The odometer of a car reads 3000 km at the start of a trip and 3400 km at the end of the trip. If the trip took 8 hours, calculate the average speed of the car in km $h^{-1}$.

1. $20km{h}^{-1}$
2. $50km{h}^{-1}$
3. $75km{h}^{-1}$
4. $150km{h}^{-1}$

Q. A swimmer swims in a $90m$ long pool. He covers the distance of $180m$ by swimming from one end to other end and back along the same path. If he covers the first $90m$ at a speed of $2m{s}^{-1}$, then how fast does he swim such that his average speed is $3m{s}^{-1}$?

1. $5m{s}^{-1}$
2. $6m{s}^{-1}$
3. $2m{s}^1$
4. $3m{s}^{-1}$

Q. a particle moves for 20s with speed 6m/s and then the speed 8m/s for another 20s and finally moves with speed 10m/s for next 20s what is the average speed of the particle?

Q.

A thief passes a policeman at a velocity of 15 m/s. The police car starts chasing with acceleration of $2m{s}^{-2}$. Find the time taken by the policeman to catch the thief if the police car started from rest.

Q. Question 3
Abdul, while driving to school, computes the average speed for his trip to be $20kmph$. On his return trip along the same route, there is less traffic and the average speed is $40kmph$. What is the average speed for Abdul’s trip?

Q.

A motorist drives north for $35min$ at $85km{h}^{-1}$ and then stops for $15min$. He next continues north, travelling $130km$ in $2h$.

(a) What is his total displacement?

(b) What is his average velocity?

Q.

Ria’s mother told her that initial velocity and final velocity of the car during overtake were 150 km/h and 168 km/h respectively. What was the acceleration of the yellow car if overtake happened in 2.5 seconds?

Q.

The correct symbol to represent the speed of an object is

1. $\raisebox{1ex}{$5m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$

2. $\raisebox{1ex}{$5m$}\!\left/ \!\raisebox{-1ex}{$p$}\right.$

3. $5\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s^{-1}$}\right.$

4. $5\raisebox{1ex}{$s$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$

Q.

Distinguish between speed and velocity

Q.

A coin is thrown in a vertically upward direction with a velocity of $5m{s}^{-1}$. If the acceleration of the coin during its motion is $10m{s}^{-2}$ in the downward direction, what will be the height attained by the coin and how much time will it take to reach there respectively?

1. $1.5m,0.25s$

2. $0.25m,1.5s$

3. $1.25m,0.75s$

4. $1.25m,0.5s$

Q. A train begins a journey from a station and travels $60km$ in a time of $20minutes$. What is the average speed of the train?

1. $3.0m{s}^{-1}$
2. $5.0m{s}^{-1}$
3. $50m{s}^{-1}$
4. $60m{s}^{-1}$

Q.

Q.

1.It is not possible to have a situation in which speed of particle is never zero but the average speed in an interval is zero.

2. It is not possible to have a situation in which the speed of particle is always zero but the average speed is not zero.

Explain the above statements.

Q. What is the direction of the velocity at point B, if the ball is revolving clockwise?

1. Up
2. Down
3. Right
4. Left

Q. A container truck goes from Mumbai to Bangalore with an average speed of $50kmh{r}^{-1}$. The journey takes $20hours$. It returns from Bangalore to Mumbai on the same road with an average speed of $40kmh{r}^{-1}$. What was the average speed of the container during the roundtrip?

1. $44m{s}^{-1}$
2. $44kmh{r}^{-1}$
3. $4.44m{s}^{-1}$
4. $44m{s}^{-1}$

Q.

A police car travelling at a speed of 72 km/h is chasing a truck which is moving at 15 m/s. If both are 100 m apart, what will be the time taken by the Police to catch the truck?

Q. The speedometer of a car shows which of the following?

1. Average speed
2. Non uniform speed
3. Uniform Speed
4. Instantaneous Speed

Q.

A person first walks at a constant speed $v_1$ along a straight line from $A$ to $B$, and then back along the line from $B$ to $A$ with constant speed $v_2$. What is the average speed for the entire trip?

Q.

A boy releases a ball from the top of a building. it will clear the window 2m high at a distance 10m below the top in nearly.(take $g=10\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s^2$}\right.$)

1. 1s

2. 1.3s

3. 0.6s

4. 0.13s

Q.

Riya was testing the remote car she brought from the supermarket. It is completing a quarter of a circle of radius ‘R’ m in ‘t’ seconds. What is the magnitude of average velocity of the remote car?

1. 𝑅⁄𝑡 m/s

2. 0 m/s

3. (√2.𝑅)⁄𝑡 m/s

4. 2𝑅⁄𝑡 m/s

Q.

If the speed of sound in air is 340 $m{s}^{-1}$. How far does it travel in 22 seconds?

1. 2.4 km
2. 2.9 km
3. 3.4 km
4. 1.7 km

Q. A train covers $54km$ in $10minutes$. Find the speed of the train?

1. $60{ms}^{-1}$
2. $70{ms}^{-1}$
3. $80{ms}^{-1}$
4. $90{ms}^{-1}$