Forces and motion

Question 1

formula for weight

Answer 1

weight = mass X g

Question 2

What is vector

Answer 2

A quantity with direction and magnitude

Question 3

What is scalar

Answer 3

A quantity with only magnitude

Question 4

What are the different SUVAT equations

Answer 4

v= u+at
V^2= u^2 + 2as
S=ut+(at^2)/2
S = t (v+u)/2
S = vt−(at^2)/2

Question 5

What does SUVAT stand for

Answer 5

S - Displacement
U - Initial velocity
V - Velocity
A - Acceleration
T - Time

Question 6

What are:

Newton’s 3 laws

Answer 6

if an object is moving at constant velocity, the forces acting on it must be =
F = MA
If Body a exerts a force on body b, body b exerts exactly the same force in the opposite dirextion with the same magnitude

Question 7

What are the changes in:

Force experienced by a parachutist

Answer 7

1. Skydiver jumps out of the plane and is accelerating downwards at 10ms^-2. Resultant force is downwards because only weight is acting
2. A few moments later the skydiver has a velocity less than max going downwards and accelerating at <10ms^-2 as air resistance kicks in. Resultant force is downwards
3. Terminal velocity is reached as drag is equal to weight and there is no acceleration. Velocity is going downwards at the maximum speed. Resultant force is 0.
4. The parachute is pulled and the AR has a very large arrow upwards, but the velocity has not changed. Resultant force is upwards.
5. A few moments later the acceleration is still upwards, but less, and the velocity is downwards and less than max. Resultant force is upwards, but less than a few moments before.
6. A new terminal velocity is reached as AR = W. The acceleration is 0 and the new terminal velocity is much smaller than the other one. The velocity is still going downwards. Terminal velocity is 0.