Following figure is the speed-time graph for a rocket from the moment when the fuel starts to burn, i.e. at time $t=0$.
$(a)$ State the acceleration of the rocket at $t=0$.
$(b)$ State what happens to the acceleration of the rocket between $t=5 s$ and $t=60 s$.
$(c)$ Calculate the acceleration of rocket at $t=80 s$ Give reason for your answer.
$(d)$ The total mass of the rocket at $t=80\, s$ is $1.6 \times 10^{6}\, kg .$ Calculate the resultant force on the rocket at this time. Give reason for your answer.
$(a)$ No net acceleration, balanced force between burning of fuel and gravitational acceleration.
$(b)$ Increases after $10$ sec, till $t=50$ s; zero acceleration after $50$ sec because it attains constant velocity.
$(c)$ Zero.
$(d)$ Zero as it is moving with constant velocity.
Starting from rest at the top of an inclined plane a body reaches the bottom of the inclined plane in $4$ second. In what time does the body cover one$-$fourth the distance starting from rest at the top ?
What is the nature of motion of a particle depicted by following displacement$-$time graphs ?
State the meaning of uniform circular motion.
A body thrown in the vertically upward direction rises upto a height $'h^{\prime}$ and comes back to the position of its start.
Calculate :
$(a)$ the total distance travelled by the body and
$(b)$ the displacement of the body. Under what condition will the magnitude of the displacement be equal to the distance travelled by an object ?
What is the numerical ratio of average velocity to average speed of an object when it is moving along a straight path ?