An unknown 20.0 g object heated to 100°C was placed in 50.0 g of water. Initially, the water was at 25.0°C, and the final temperature of the water + object was 30.0°C. Assuming no heat loss, and a specific heat of water = 1.0cal/g·°C, use the relationship Q=mCsp∆T to determine the unknown’s specific heat.

A1000-kg weather rocket is launched straight up. the rocket motor provides a constant acceleration for 16-s, then the motor stops. the rocket altitude 20-s after launch is 510-m. you can ignore any effects of air resistance. a. what was the rocket’s acceleration during the first 16-s? b. what is the rocket’s speed as it passes through a cloud 5100-m above the ground?

Marcella is a four-year-old girl who is a victim of emotional child abuse. based on the child and family services improvement and innovation act of 2011, which action should the government take for marcella? a. the state should arrest marcella’s abuser. b. the state should find a home for marcella as soon as possible. c. the state should enforce stricter laws in the area where marcella resides. d. the state should provide medical assistance to marcella.

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?