Velocity

Q.

A ball is thrown vertically upwards. It goes to a height of 20 m and then returns to the ground. Taking acceleration due to gravity g to be 10 m/$s^2$ . Find the initial and final velocity of the ball and also find the time.

Q.

How can acceleration be zero when velocity is constant?

Q.

A ball is thrown vertically upward from the top of a tower with an initial velocity of 19.6 metre per second. The ball reaches the ground after 5s. Calculate

A. The height of the tower

B. The velocity of ball reaching the ground

Q.

A ball is projected from a certain point on the surface of a planet at a certain angle with the horizontal surface

The horizontal and vertical displacement x and y vary with time t in seconds v as :

X = 10*3^1/2 t

Y = 10t-t^2

The maximum height by ball is?.

Q.

Under what condition is the magnitude of average velocity of an object equal to its average speed?

Q.

A sprinter in a 100 m race, covers 4 m in 1 second, 30 m in the next 4sec, 52 m in another 4 sec and finishes the race in 10 sec. Calculate the average velocity of the sprinter?

Q.

When an object is thrown in vertically upward direction, why the final velocity is 0

Q.

A body moving with constant acceleration but with zero velocity. state whether the given situation is possible? explain giving an example.

Q.

The velocity of a body changes

1. only if its speed changes

2. only if its direction changes

3. if either its speed or direction changes

4. if the acceleration is zero

Q.

A stone is thrown with an initial speed of $4.9{\mathrm{ms}}^{-1}$ from a bridge in vertically downward direction. It falls down in water after $1$second. Find the height of bridge.

Q.

When a body moving with a speed of 20 m/s. stops in 20 seconds, what is the acceleration?

1. 2 m/s²

2. -1 m/s²

3. -2 m/s²

4. 3 m/s²

Q.

If a moving body comes to rest, then its acceleration is-

1. Positive

2. Zero

3. All of these depending upon initial velocity

4. Negative

Q.

Suppose a ball is thrown vertically upward then is the time taken to reach the zero velocity(while going up) is equal to time taken to come to the same position(from where it was thrown) or ground . If yes , give the reason

Q. The velocity of a car is $18m{s}^{-1}$. Express this velocity in $km{h}^{-1}$.

1. 64.8 km/h

2. 70 km/ hr

3. 76 km/h

4. 65.7 km/h

Q.

A ball A is thrown up vertically with speed u.At the same instant another ball B is released from rest at height h.At time t speed of A relative to B is ?

Q. An object moving in a circular track of radius $7m$ completes one full revolution of the track in $7$ seconds. Its speed during the motion will be:

1. $7m{s}^{-1}$
2. $2\pi m{s}^{-1}$
3. $14m{s}^{-1}$
4. $\pi m{s}^{-1}$

Q. The velocity of an object increases at a constant rate from 20m/s to 50m/s in 10s.Find the acceleration

Q.

A person standing on the edge of a cliff at some height above the ground throws the first ball straight up with an initial velocity u and then throws the second ball straight down with the same initial velocity u. Which of the following statement is TRUE regarding their velocities when they hit the ground?

1. Both the balls will have the same velocity when they hit the ground.

2. First ball will have higher velocity than the second.

3. Can’t say as final velocity depends on other factors as well.

4. Second ball will have higher velocity than the first.

Q. Derivation of second equation of motion is:

1. $d\theta =wd2t$
2. $d\theta =wdt$
3. $d\theta =wd3t$
4. $d\theta =wd{t}^2$

Q.

A body moves due East with velocity $20kmh{r}^{-1}$ and then due North with velocity $15kmh{r}^{-1}$. The resultant velocity in $kmh{r}^{-1}$

1. $5$

2. $15$

3. $20$

4. $25$

Q.

A ball is thrown vertically upwards from the top of a tower with an initial velocity of 19.6m/s. The ball reaches the ground after 5s. Calculate

1. The height of the tower

2. The velocity of ball on reaching the ground.

(Take g=9.8m/s)

Q.

A body moves in a plane so that the displacement along the $X$ and $Y$–axes is $x=3t^2$ and $y=4t^2$, then velocity is

1. $15t^2$

2. $20t^2$

3. $5t^2$

4. None of these

Q. For uniform motion, the slope of the -time graph is zero.

1. displacement
2. speed
3. velocity

Q. Which of the following graphs represent an object moving with a non-uniform accelerated motion ?

1. Q & R only
2. P only
3. R & S only
4. S only

Q.

A body has an initial velocity 5 $m{s}^{-1}$. It is accelerating at 2 $m{s}^{-2}$. It's velocity after 10 second is

1. $20m{s}^{-1}$

2. $25m{s}^{-1}$

3. $15m{s}^{-1}$

4. $10m{s}^{-1}$

Q. A person running on a circular track of radius 40 m completes one round in 80 s. Find the average velocity. ​
(Take π = 3.14)​

1. 5.5 m/s​
2. 5 m/s​
3. 0 m/s
4. 3.14 m/s

Q.

A particle starts from rest and moves with constant acceleration. Its distance x and velocity v is related as

1. $x\propto v$

2. $x\propto v^2$

3. $x\propto v^3$

4. $x\propto v^4$

Q. What is angular velocity?

Q.

If only the direction of an object changes, then the object is in motion.

1. False

2. True

Q.

A ball is thrown vertically upward with a speed of 10m/s from the top of a tower 200m high and another is thrown vertically downward with the same speed simultaneously. The time difference between them in reaching the ground in s is?