kzur123
Answered

A car covers 72 kilometers in the first hour of its journey. In the next hour, it covers 90 kilometers. What is the amount of work done by the car? The total mass of the car, including its passengers, is 2.5 × 103 kilograms.

A2.8 × 105 joules
B4.0 × 105 joules
C5.1 × 105 joules
D2.8 × 106 joules
E2.8 × 107 joules

Verified Answer :

metchelle

The amount of work done can be solved using the formula:

Work = Force x Distance = Change in kinetic energy

Kinetic energy can be solved using the formula: KE = (1/2)mv^2
So, change in kinetic energy = (1/2)m(Vf)^2 - (1/2)m(Vo)^2

Where:

Vf = final velocity = 90 kph = 25 m/s
Vo = initial velocity = 72 kph = 20 m/s

substituting the given values:

Work = (1/2)2500(25^2) - (1/2)2500(20^2) = 281250 J, which can also be expressed as 2.8 x 10^5 Joules.

Among the choices, the correct answer is A.

KINGOFSPADES99

Answer:

(1/2)2500(25^2) - (1/2)2500(20^2) = 281250 J, which can also be expressed as 2.8 x 10^5 Joules.

Explanation:

Related Questions