Question

A spring balance is attached to 2 kg trolley and is used to pull the trolly along a flat surface as shown in the fig. The reading on the spring balance remains at 10 kg during the motion. The acceleration of the trolly is

Answer 1

The reading on the spring balance = m
so the tension force applied = mg
In the above case 
m₁a = mg
m₁ is the mass of the trolley and m is the Reading on the spring balance;
2*a = 10*9.8
⇒ a = 49 m/s²
Answer the acceleration of the trolley is 49 m/s²

Answer 2

Let a be the acceleration of the trolley we have to find.

2 x a = 10 x 9.8
a = 49 m/s²

The acceleration of the trolley is 49 m/s²