Advertisements
Advertisements
Question
Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?
Advertisements
Solution
- An object's acceleration could be zero even when several forces are acting on it. This happens when all the forces cancel out each other, i.e., the net force acting on the object is zero.
- For a uniformly moving object, the net force acting on the object is zero.
- Hence, the acceleration of the object is zero. Hence, Soni is right.
- Then, according to the equation F = ma, the mass of the object.
- Acceleration = `F/m` (since F = 0) will also be zero.)
APPEARS IN
RELATED QUESTIONS
What are the two kinds of mechanical energy?
A boy of weight 40 kgf climbs up the 15 steps, each 15 cm high in 10 s and a girl of weight 20 kgf does the same in 5 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1.
Is work done a scalar or a vector physical quantity?
A weight lifted a load of 200 kgf to a height of 2.5 m in 5 s. calculate: (i) the work done, and (ii) the power developed by him. Take g= 10 N kg-1.
A canon ball of mass 500g is fired with a speed of 15m/s-1. Find: its momentum.
How much energy is gained by a box of mass 20 kg when a man, runs carrying the box with a speed of 3 m/s-1 to catch the bus?
A coolie, with a load of 30 kg on his head, walks on the platform. If he walks a distance of 60 m, what is the work done by him?
A block of mass 30 kg is pulled up a slope, as shown in diagram with a constant speed, by applying a force of 200 N parallel to slope.
A and B are initial and final positions of block.
(i) Calculate the work done by force in moving the block from A to B.
(ii) Calculate P.E. gained by block. [g=10ms-2]
