A stone is dropped from the roof of a high building. A second stone is dropped 1.25 s later. How long does it take for the stones to be 25.0 meters apart?

# Tag: lightyear

Explain a possible situation where you start with a positive velocity that decreases to a negative increasing velocity while there is a constant negative acceleration.

A sports car moving at constant speed travels 150 m in 4.00 s. If it then brakes and comes to a stop while decelerating at a rate of 6.0 m/s2 , how long does it take to stop?

A car travels 120 meters in one direction in 20 seconds. Then the car returns ¾ of the way back in 10 seconds. Calculate the average speed of the car for the first part of the trip. Find the average velocity of the car.

Problem 4 What is larger 4000 L or $latex 4\times 10^5\:cm^3&s=2&fg=000000$ (and you must show your reasoning.) Solution: There are $latex 1000\:or\:1\times 10^3\:cm^3&s=1&fg=000000$ in 1 L. So, in $latex 4\times 10^5\:cm^3&s=1&fg=000000$ there are $latex 4\times 10^5\:cm^3\times \left(\frac{1\:L}{1\times 10^3\:cm^3}\right)=400\:L&s=1&fg=000000$ Therefore, the 4000 L is larger than $latex 4\times 10^5\:cm^3&s=1&fg=000000$.

Problem 3 What is the surface area of a sphere of diameter $latex 2.4\times 10^2&s=2&fg=000000$ cm? Solution: $latex SA=4\pi r^2=4\pi \left(\frac{2.4\times 10^2\:cm}{2}\right)^2=1.8\times 10^5\:cm^2&s=1&fg=000000$

Problem 2 Multiply $latex 1.783\times 10^{-2}\cdot 4.4\times 10^{-3}&s=1&fg=000000$, taking into account significant figures. Solution: $latex 1.783\times 10^2\cdot 4.4\times 10^{-3}=0.78\:or\:7.8\times 10^{-1}&s=1&fg=000000$

Problem 1 One lightyear is defined to be the distance light can travel in one year. What is this distance in meters? How long does it take for light to get to the Moon? Solution: $latex 1\:lightyear=9.461\times 10^{15}\:m&s=1&fg=000000$ The approximate distance from Earth to the moon is 384,400 kilometers. The time it takes for the … Continue reading Grantham PHY220 Week 1 Assignment Problem 1