6.5.4.2.2 newton’s second law

Question 1

Newton’s second law states that:

Answer 1

The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object.

Question 2

What is the equation for resultant force?

Answer 2

resultant force (F, newtons) = mass (m, kg) x acceleration ( a, m/s ²)

Question 3

What is terminal velocity?

Answer 3

When the air resistance (opposing force) is equal to the force of gravity causing the object to fall at a constant speed

Question 4

What is the resultant force

Answer 4

The difference between the forward and backward force- not equal to each other.

Question 5

What is the equation for acceleration?

Answer 5

Acceleration (a, m/s ²) = force applied to object (F, newtons) / mass (m, kg)

Question 6

Does the acceleration decrease or increase when the force is increased?

Answer 6

increases

Question 7

Does the acceleration decrease or increase when the mass increases

Answer 7

Increases

Question 8

What is the equation for force (acceleration and mass)

Answer 8

force (F, newtons) = mass (m, kg) x Acceleration (a, m/s ²)

Question 9

What is the force of gravity within Earth’s atmosphere

Answer 9

10N/kg / 10m/s ²

Question 10

If you were to place both a feather and a piece of lead in a vacuum (including no oxygen) would they both fall at the same rate and hit the floor at the same time or fall at different rates and hit the floor at different times?

Answer 10

they have the same rate when falling and would hit the ground at the same time

Question 11

What is the equation for weight?

Answer 11

weight (W, newtons) = mass (m, kg) x gravitational field strength (g, N/kg)

Question 12

If a rocket has a mass of 50kg, and an upwards thrust of 1,000 N, what is the acceleration?

Answer 12

1st - calculate the weight (50x10= 500N)
2nd - the resultant upwards thrust is 1000N - 500N = 500N
3rd- Acceleration = 500 / 50
4th- Acceleration = 10m/s ²

Question 13

What is Newton’s first law?

Answer 13

A body will remain in its present state of motion unless acted upon by an external force

Question 14

What is meant by ‘present state of motion’ ? (Newtons 1st law)

Answer 14

Standing still or travelling at a constant speed, (force needed to make object slow down or change direction)

Question 15

When a car is travelling at constant speed, the forward force is ______ to the opposing force?

Answer 15

Equal.

Question 16

To make a car accelerate the forward force has to be _______ than the opposing force

Answer 16

Larger

Question 17

To slow a car down (decelerate) the forward force has to be _______ than the opposing force

Answer 17

Smaller- braking causes friction between the tyres and the road surface.