Question

3.
A 2,000-kilogram car uses a braking force of 12,000 newtons to stop in 5 seconds.
a. What impulse acts on the car?
b. What is the change in momentum of the car?
c. What is the initial speed of the car?

Answer 1

Explanation:

m = 2,000-kilogram

F = 12,000

t = 5 seconds

a) Impulse (I) = Ft = 12000 × 5

I = 60,000 Ns

b) from Newton's 2nd law

F = m∆v/t

Ft = m∆v

change in momentum (∆p) = 60,000kgm/s

c) ∆v = Ft/m = 60,000/2000 = 30m/s

the initial velocity is 30m/s since final velocity is zero

Momentum …

is a quantity that describes an object's

resistance to stopping (a kind of "moving

inertia"). and is represented by the symbol p which is the product of an object's mass and velocity.

p = m v

is a vector quantity (since velocity is a

vector and mass is a scalar).

Impulse …

is a quantity that describes the effect of a

net force acting on an object (a kind of

"moving force").

is represented by the symbol I

is the product of the average net force

acting on an object and its duration.

I = F Δ t

Answer 2

(a) The impulse that acts on the car is 60,000 N.s.

(b) The change in momentum of the car is 60,000 N.s.

(c) The initial velocity of the car is 30 m/s.

The given parameters;

• mass of the car, m = 2,000 kg
• force applied on the car, F = 12,000 N
• time of motion, t = 5 s

The impulse that acts on the car is calculated as follows;

J = ft

J = 12,000 x 5

J = 60,000 N.s

The change in momentum of the car is calculated as follows;

ΔP = J

Δ = 60,000 N.s

The initial velocity of the car is calculated as follows;

$F = ma = \frac{mv}{t} \\\\mv = Ft\\\\v = \frac{Ft}{m} \\\\v = \frac{60,000}{2,000} \\\\v = 30 \ m/s$

Learn more here:https://brainly.com/question/18772631