Given, Mass of the stone (m) = 1 kg

Initial velocity (u) = 20 m/s

Terminal velocity (v) = 0 m/s (the stone reaches a position of rest)

Distance travelled by the stone (s) = 50 m

As per the third motion of equation, (v^{2} - u^{2}) = 2as

The acceleration of the stone is given by : \( \frac{(v^2 - u^2)}{2s}\)

Therefore, acceleration of the stone (a) = \( \frac{0-400}{100}ms^2 =-4 \,ms^{-2}\)

As per the second law of motion, F = ma

Therefore, force acting on the stone, \( F = 1kg\, \times\,-4ms^2=-4\,N\)

The frictional force acting on the stone has a magnitude of 4 N and it acts on the direction opposite to that of stone's motion

Answered by Shivani Kumari | 2 years agoA motorcar of mass 1200 kg is moving along a straight line with a uniform velocity of 90 km/h. Its velocity is slowed down to 18 km/h in 4 s by an unbalanced external force. Calculate the acceleration and change in momentum. Also calculate the magnitude of the force required

A hammer of mass 500 g, moving at 50 m s^{-1,} strikes a nail. The nail stops the hammer in a very short time of 0.01 s. What is the force of the nail on the hammer

Two persons manage to push a motorcar of mass 1200 kg at a uniform velocity along a level road. The same motorcar can be pushed by three persons to produce an acceleration of 0.2 m s^{-2}. With what force does each person push the motorcar? (Assume that all persons push the motorcar with the same muscular effort)

**The following is the distance-time table of an object in motion:**

Time (seconds) |
Distance (meters) |

0 | 0 |

1 | 1 |

2 | 8 |

3 | 27 |

4 | 84 |

5 | 125 |

6 | 216 |

7 | 343 |

**(a)** What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?

**(b)** What do you infer about the forces acting on the object?

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