Question

velocity versus time graph of a ball of mass 50Kg rolling on a concrete floor is shown in figure given below. Calculate the acceleration & frictional force of the floor on the ball .

Answer 1

Answer :

➥ The acceleration = -10 m/s²

➥ The frictional force of the floor on the ball = -0.5 N

Given :

From the above graph,

➤ Intial velocity (u) = 80 m/s

➤ Final velocity (v) = 0 m/s

➤ Time taken (t) = 8 sec

➤ Mass (m) = 50 kg

To Find :

➤ Acceleration (a) = ?

➤ Frictional force of the floor on the ball = ?

Solution :

We can find Acceleration by using the first equation of motion which says v = u + at, So let's calculate a !

→ v = u + at

→ 0 = 80 + a × 8

→ a = -80/8

→ a = -10 m/s²

║ Hence, the acceleration is -10 m/s². ║

To find the frictional force of the floor on the ball first we need to convert the mass gram intro kg, then after we find the frictional force of the floor on the ball from the force formula.

◈ m = 50 g

→ m = 50/1000 kg

→ m = 1/20 kg

Now, we have mass of the object and it's acceleration,

• Mass of the object (m) = 1/20 kg
• Acceleration (a) = -10 m/s²

☃️ So let's find frictional force of the floor on the ball by using the formula: $\:$

As we know that

→ F = ma

→ F = 1/20 × (-10)

→ F = 0.05 × (-10)

→ F = - 0.5 N

║ Hence, the frictional force of the floor on the ball is -0.5 N. ║

【NOTE :- Negative sign is showing the frictional force of the floor on the ball.】