Question

A force of 20 N pushes an object of mass 5.0 kg along a rough horizontal surface where the frictional force is 5.0 N. What is the acceleration of the object?

A]1.0 m/s
B}2.0 m/s*
C} 3.0 m/s
D} 4.0 m/s?

Answer 1

Answer:

C:3.0m/s

Explanation:

The right answer to this question is 3.0m/s.

As it's stated that a force of 20N pushes the object, but due to frictional force of 5.0N the resultant force is 15.0N.

We then use the formula of acceleration which is acceleration=force/mass (a=f/m). The answer then becomes a=15/5 which is 3.0m/s.

Answer 2

Given:

A force of 20 N pushes an object of mass 5.0 kg along a rough horizontal surface where the frictional force is 5.0 N.

To find:

Net acceleration of object ?

Calculation:

• First of all, let's find the net force on the object.

$F = F_{applied} - f$

$\implies F = 20 - 5$

$\implies F = 15 \: N$

Now, net acceleration of the object :

$\implies a = \dfrac{ F}{m}$

$\implies a = \dfrac{15}{5}$

$\implies a = 3 \: m/ {s}^{2}$

So, net acceleration is 3 m/s² (option C)