A child pulls a toy across the floor. Is the work done on the toy positive, negative, or zero?

Which of the following is NOT an effective pre-exercise energizing snack?

Reggie and Charlotte are baking oatmeal cookies. They dip the baked cookies in melted chocolate. The chocolate cools to form a hardened coating. Reggie argues the entire chocolate-covered cookie has undergone a chemical change.

Alejandra weighs 225 newtons. how much work does she do against gravity when she climbs to a ledge at the top of a 15 meter climbing wall

If a 1-megaton nuclear weapon is exploded at ground level, the peak overpressure (that is, the pressure increase above normal atmospheric pressure) will be 0.2 atm at a distance of 6 km. Atmospheric pressure is 1.013 * 10^5 Pa.

What is the time lapse between seeing a lightning strike and hearing the thunder if the lightning flash is 47 km away? The speed of light waves in air is 3 * 108 m/s and the speed of sound waves in air is 333 m/s.

What is the average speed in miles per hour of the car that traveled a total of 200 miles in 5.5 hours

A solid weighs 277.5 g in air and 212.5 g when totally immersed in the liquid of density 0.9 g / cc. Calculate the density of the solid.

Who first described the double-helix structure of DNA?

Suppose you are holding a basketball while standing still on a skateboard you are and the skateboard have a mass of 50 kg you throw the basketball with a force of 10 N what is your acceleration before and after you throw the ball

Which nitrogen base sequence is the partner of C-A-T-C-G-A? O C-A-T-C-G-A O G-T-A-G-C-T OT-G-C-T-A-G O G-C-A-T-G-T TI