Grade-11_Motion in a Straight Line

A car covers first 2 km of the distance of 4 km with speed of 30 km/h and the remaining distance of 2 km with a speed of 20 km/h . The average speed of the car is

• 24 km/h

• 25 km/h

• 50 km/h

• 26 km/h

A vehicle travels half the distance L with speed u and the other half with speed V then its average speed is

• $\frac{\left(u+v\right)}{2}$

• $\frac{\left(2u\ +v\right)}{u\ +v}$

• $\frac{2uv}{u+v}$

• $\frac{L\left(u+v\right)}{uv}$

A spring with one end attached to a mass and the other to a rigid support is stretched and released.

• Magnitude of acceleration, when just released is maximum.

• Magnitude of acceleration, when at equilibrium position, is

  maximum.

• Speed is maximum when mass is at equilibrium position.

• Magnitude of displacement is always maximum whenever speed is minimum.

A particle is moving along  $\chi$  axis. The position of the particle at any instance is given by  $\chi$  = 5 + 6 $t^2$  , where  $\chi$   is in meters t in second

•  $5\ ms^{-1}$  

•  $10\ ms^{-1}$  

•  $12\ ms^{-1}$  

•  $24\ ms^{-1}$  

A boy completes a semicircles of radius 7m in 5 seconds. The distance travelled by the boy is

• 7 m

• 10 m

• 11 m

• 22 m

A body is thrown upward and after some time the body reaches it’s maximum height, At maximum height:

• It’s velocity and acceleration both are zero.

• It’s velocity is zero and acceleration is maximum

• It’s velocity is maximum and acceleration is minimum

• It’s velocity is zero and acceleration is equal to acceleration due to gravity(g).

The displacement -time graphs of two particles A and B are straight lines inclined at angle 30° and 60° with the time axis. the ratio of V_A : V_B must be:

• 1:2

• 1:√3

• √3:1

• 1:3

A body is thrown with speed 20m/s vertically upward , It will return to thrower’s hand after a time of:(assume g=10m/s²)

• 2s

• 4s

• 20s

• never

A ball is thrown vertically upward from the ground with an initial velocity of 160 ft per second.  It's position is defined by the following function.  When will the ball reach its maximum height?

• 0 seconds
• 10 seconds
• 5 seconds
• 32 seconds

What type of motion does section D show?

• Stationary

• Constant Speed

• Accelerating

• Decelerating

• Can't say