Planets in our solar system do not revolve around the sun in perfect circles. Their orbits are more like ovals that scientists describe as elliptical. It is one of Kepler's laws. The sun is the focus of all the planets. The correct answer is D.

7 0

3 years ago

An engine is used to lift a beam weighing 9,800 N up to 145 m. How much work must the engine do to lift this beam? How much work

Arturiano [62]

Explanation:

Given that,

Weight of the engine used to lift a beam, W = 9800 N

Distance, d = 145 m

Work done by the engine to lift the beam is given by :

W = F d

$W=9800\ N\times 145\ m\\\\W=1421000\ J\\\\W=1421\ kJ$

Let W' is the work must be done to lift it 290 m. It is given by :

$W'=9800\ N\times 290\ m\\\\W'=2842000\ J\\\\W'=2842\ kJ$

Hence, this is the required solution.

5 0

3 years ago

A racecar driver steps on the gas, and his racecar travels 20 meters in 2 seconds starting from rest. The acceleration of the ra

givi [52]

Answer:

2.5m/s^2

Explanation:

Step one:

given

distance = 20meters

time = 2 seconds

initial velocity u= 0m/s

let us solve for the final velocity

velocity = distance/time

velocity= 20/2

velocity= 10m/s

$v^2=u^2+2as\\\\10^2=0^2+2*a*20\\\\100=40a$

divide both sides by 40

$a= 100/40\\\\a=10/4\\\\a= 5/2\\\\a= 2.5m/s^2$

5 0

3 years ago