physics........?

Question

Given: 5000kg truck travellling 60km/hr
a. what is its momentum in terms or Kg m/s
b. if it were to be stopped by a constant retarding force in 10s, what must be its negative acceleration?
c. what is the retarding force?
what is the impulse on the truck?

Answer 1

Convert 60 km/hr to m/s. This will be the initial velocity of the truck in m/s.

a) momentum = mass x velocity

b) acceleration = (final velocity - initial velocity) / time

The final velocity is zero since the truck has stopped.

c) Force = mass x acceleration

Impulse = Force x time

The impulse will equal the change in momentum. Since the final momentum is zero (the car has stopped), The impulse will be equal to the result in (a).

Answer 2

A) First, convert km/h to meters per second.
(60 km/hr)(1000 m/1km)(1 hr/60min)(1min/60s)
I'm sure you can figure out momentum from here.
B) Now that you have velocity in m/s, you can calculate acceleration:
a = change in speed/time = velocity from part A/10 seconds
C) F = ma
Force = mass times acceleration. You know the mass, you just calculated the acceleration, so...
D) I=Ft
Impulse = force times time. You know the force, you know it took 10 seconds, so...

Answer 3

a)83333 1/3 (speed in m/s *weight)

b) it decelerates at 1 2/3 m/s/s or ms^-2 (speed/deceleration time)

c)83333 1/3 N or kg m/s/s or kg ms^-2 against the truck((speed change/time)*weight) it is also equal to the momentum

i don't know what you mean by the impulse on the truck

Answer 4

a. momentum
=mv
=5000x60x1000/3600
=8.33X10^4 Kg m/s
b.u=16.7m/s,v=0,t=10s

So,v=u+at
0=16.7+10a
a=-1.67m/s^2

c.F=ma
=5000x1.67
=8.33x10^3N
so impulse
=Ft
=8.33x10^3x10
=8.33x10^4kg m/s