# Universal Units, engineering homework help

Science

1) If a ball is dropped from a height (H) its velocity will increase until it hits the ground (assuming that aerodynamic drag due to the air negligible). during its fall, its initial potential energy is converted into kinetic energy if the ball is dropped from a height of 800 centimeters and the impact velocity is 41 feet per second, determine the value of gravity in units of meter per second.

2) A robotic rover on Mars finds a spherical rock with a diameter of 10 centimeters. The rover picks up the rock and lifts it 20 centimeters straight up. The rock has a specific gravity of 4.75. The gravitational acceleration on Mars is 3.7 meters per second squared. If the robot’s lifting arm has an efficiency of 40% and require seconds to raise the rock 20 centimeters, how much power in watts did the arm use?

3) A 100-watt motor (60% efficient) is used to raise a 100-kilogram load 5 meters into the air. If the task takes 65 seconds to complete, how heavy was the load in units of kilograms?