A box weighs 300N. A force of 20N slide it across a floor at a constant speed. What is the mass of the box? What is the acceleration of the box?

Mass = 30kg

Acceleration = 0m/s/s

Explanation:

The weight of an object is its mass multiplied by the gravitational field strength. On Earth the value often used for gravity is 10N/kg. This means there is 10N of force per kg of mass, so the weight of an object will be 10x its mass. Here we are given a weight of 300N, so to find its mass we simply need to divide it by 10. 300/10 = 30kg. The mass of the box is 30kg.

Because the box is being slid across the floor at a constant speed, the velocity is not changing, therefore the acceleration is 0.

Hope this helped!

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me