Advertisements
Advertisements
प्रश्न
A metal ball of mass 5 kg falls from a height of 490 m. How much time it will take to reach the ground? (g = 9.8 m/s2)
Advertisements
उत्तर
Given, Mass (M) = 5 kg.
Distance travelled by the ball (s) = 490 m
Initial velocity of the ball (u) = 0
Gravitational acceleration (g) = 9.8 m/s2
Newton's second equation of motion gives
s = `"ut" + 1/2 "gt"^2`
∴ 490 = `0 xx "t" + 1/2 xx 9.8 xx "t"^2` .....[Initial velocity (u) = 0]
⇒ 490 = 4.9 t2
t2 = `490/4.9`
t2 = 100
t = 10 sec.
∴ The ball takes 10 seconds to reach the ground.
APPEARS IN
संबंधित प्रश्न
What do you mean by free fall?
What do you mean by acceleration due to gravity?
What is the acceleration produced in a freely falling body of mass 10 kg ? (Neglect air resistance)
State whether the following statement is true or false :
The acceleration due to gravity acting on a freely falling body is directly proportional to the mass of the body.
What do you mean by the term free fall ?
What is the usual value of the acceleration due to gravity of earth ?
Explain why, the tip of a sewing needle is sharp.
A stone is thrown vertically upwards with initial velocity u reaches a height ‘h’ before coming down. Show that the time taken to go up is the same as the time taken to come down.
A ball falls off a table and reaches the ground in 1 s. Assuming g=10 m/s2, calculate its speed on reaching the ground and the height of the table.
Choose one or more correct alternatives.
Which of the forces involved in dragging a heavy object on a smooth, horizontal surface, have the same magnitude?
- The horizontal applied force
- gravitational force
- reaction force in vertical direction
- force of friction
A force of 15 N acts on a body of mass 2 kg. Calculate the acceleration produced.
Figure shows the velocity-time graph of a particle of mass 100 g moving in a straight line. Calculate the force acting on the particle.
(Hint : Acceleration = Slope of the v-t graph)
Define the term acceleration due to gravity? Write its S.I. unit.
What is escape velocity?
State whether the below statement is True or False.
Neglecting air resistance, a body falling freely near the earth's surface has a constant acceleration.
Explain why:
Objects fall to the earth.
Write scientific reason.
The value of gravitational acceleration (g) decreases as we go deep inside the earth.
Write acceleration due to gravity value on the surface of Earth.
