Question

A 1.0 kg bal is thrown up with a speed of 9.9 metre per second. calculate the work done by its weight in one second.​

Answer 1

Given:-

• Mass of Ball (m) = 1kg

• Initial Velocity of Ball (u) = 9.9m/s

• Time taken (t) = 1 s

• Acceleration due to gravity (g) = 9.8 m/s²

TO Find:-

• Work done by its weight in one second.

Solution:-

According to the Given Question

we have to calculate the work done by its weight in one second. So, firstly we need to find the distance covered by the ball.

By Using this Formula

⟹ s = ut -1/2gt²

Putting all the values which is given above

⟹ s = 9.9×1 -1/2 × 9.8 × (1)²

⟹s = 9.9 - 4.9 × 1

⟹ s = 9.9 - 4.9

⟹ s = 5 m

Thus, the distance covered by ball in one second is 5m.

Now,

Force is the product of mass and acceleration

⟹ F = m×a

⟹ F = 1 × 9.8

⟹ F = 9.8 N

9.8 N Force acting in the downward direction

Work Done = Force × Displacement

⟹ W = F×S

⟹ W = (-9.8) × 5

⟹ W = - 49 J

Therefore,the work done in one second is -49 J

Answer 2

Answer =

mass of object=1 kg

velocity=9.9m/s

Work done =kinetic energy=1/2 mv2

=1/2 *9.92*1

=49.005 J