Physics Answers

the minimum distance required to stop a car moving at 35 mi/h is 42.6 ft what is the minimum stopping distance for the same car moving at 70 mi/h

Two boats start together and race across a 60-km-wide lake and back. Boat A goes across at 60 km/h and returns at 60 km/h. Boat B goes across at 30 km/h, and its crew, realizing how far behind it is getting, returns at 90 km/h. Turnaround times are negligible, and the boat that completes the round trip first wins. 

can i just use 60 km/hr as average velocity for boat b

What is the velocity o π- meson whose proper means life time is 2.5× 10⅞ second

A pencil has a mas of 200 grams. If it is placed one meter above the ground, what would be its kinetic energy upon hitting the ground?

A coin is placed at the top of a two-story building, having a potential energy of 20 J. If it has a mass of 2.50 grams, what would be its velocity upon hitting the ground?

How much work is required to accelerate a 1500kg car from 15 m/s to 40 m/s?What is the average net force acting on the car if it covers a distance of 275m? 

A 70N force is applied horizontally to a 10kg block at rest for a displacement of 200m across a frictionless surface. How much work is done by the force? What is the acceleration of the block?

The speed v in a gas can reasonably be dependent on the pressure p, the density p, and the volume V of the gas. Using dimensional analysis, determine the exponents l,m and n in the formula v=Cp^lp^mV^n

Interestingly, when the value of G was first measured, people all over the world were very excited because the mass of the earth can now be measured through Newton's law of universal gravitation. Using the radius of the earth, r = 6.40 X10 m, calculate its mass Consider a 1 Kg ball on the floor.