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AutumnBeds

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Hi, I've been asked to solve below as part of an assignment. Below is pretty much what I've submitted but it has been concluded to be incorrect. I am unsure as to why hence the question. Is it due to the fact that I have not taken the mass or forces into consideration?

I have only taken these into consideration for questions (iii) and (iv) as shown below.

Any is greatly appreciated.

A racing car of mass 850 kg accelerates from 20 km/h to 160 km/h over a distance of 300 metres. Frictional forces and wind resistance can be assumed to be 800N.

Determine the following:

(i)The average acceleration

(ii)The time taken to accelerate from 20 km/h to 160 km/h

(iii)The tractive force produced by the car to provide this acceleration

(iv)The car finally reaches a speed of 250km/h. Friction and wind resistance are 1800 N at this speed. What power output is required to maintain this speed?

(i) v

(ii) s= 1/2(u+v)t

[/B]

160

160

a=42 m/s

(ii) 300= 1/2(160+20)t

t= 300/90

t= 3.3s

I have only taken these into consideration for questions (iii) and (iv) as shown below.

Any is greatly appreciated.

1. Homework Statement

1. Homework Statement

A racing car of mass 850 kg accelerates from 20 km/h to 160 km/h over a distance of 300 metres. Frictional forces and wind resistance can be assumed to be 800N.

Determine the following:

(i)The average acceleration

(ii)The time taken to accelerate from 20 km/h to 160 km/h

(iii)The tractive force produced by the car to provide this acceleration

**- not required for this thread**(iv)The car finally reaches a speed of 250km/h. Friction and wind resistance are 1800 N at this speed. What power output is required to maintain this speed?

**- not required for this thread**## Homework Equations

(i) v

^{2}=u^{2}2as(ii) s= 1/2(u+v)t

## The Attempt at a Solution

[/B]

160

^{2}=20SUP]2[/SUP]2a300160

^{2}-20^{2}/ 2 * 300 = aa=42 m/s

^{2}(ii) 300= 1/2(160+20)t

t= 300/90

t= 3.3s

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