Dynamics, forces, collisions

Question 1

What’s the unit for time

Answer 1

s

Question 2

what’s the unit for displacement and distance

Answer 2

m

Question 3

what’s the unit for acceleration

Answer 3

m s ^ -2

Question 4

What’s the unit for force

Answer 4

N

Question 5

What’s the unit for weight

Answer 5

N

Question 6

What’s the unit for energy

Answer 6

J

Question 7

What’s the unit for power

Answer 7

W

Question 8

what’s the unit for momentum

Answer 8

kg m s ^ -1

Question 9

what’s the symbol for momentum on the formula sheet?

Answer 9

p

Question 10

what’s the symbol for impulse on the formula sheet

Answer 10

there isn’t a symbol!
Impulse = Fxt

Ft=mv-mu is on the formula sheet

Question 11

If you have a graph of force against time how do you calculate the impulse?

Answer 11

It’s the area under the curve during the collsion

Question 12

What is the law of conservation of momentum?

Answer 12

Total momentum before collision is the same as total momentum after collision

Question 13

How do we write the conservation of momentum as an equation

Answer 13

m1 u1 + m2 u2

m1 v1 + m2 v2

Question 14

How can we tell if a collision is elastic?

Answer 14

Kinetic energy before collision = kinetic energy after collision

Question 15

Explain what is meant by an inelastic collision?

Answer 15

Kinetic energy before the collision is greater than kinetic energy after the collision

Question 16

Explain in terms of the forces acting on it what happens when an object reaches its terminal velocity

Answer 16

The frictional force/drag acting on
the object increases (as its
speed increases).

The frictional force/drag and weight
become balanced.

So it no longer accelerates