A 50 kg child is sitting on a scale on the floor of an elevator. The elevator starts at rest and accelerates down at a rate of a=−1 m/s2.Calculate the velocity of the elevator after 3 seconds.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

The temperature in gavin's oven is a sinusoidal function of time. gavin sets his oven so that it has a maximum temperature of 280°f and a minimum temperature of 240°. once the temperature hits 280°, it takes 20 minutes before it is 280° again. gavin's cake needs to be in the oven for 30 minutes at temperatures at or above 270°. he puts the cake into the oven when it is at 260° and rising. how long will gavin need to leave the cake in the oven? (round your answer to the nearest minute.)

Hunter’s velocity was 4.5 m/s. at the end of his race, his velocity was the same. which best describes his movement? his movement stopped. his acceleration is zero. his time was constant. his acceleration was positive.