A 4.00 g bullet is fired horizontally into a 1.20 kg wooden block resting on a horizontal surface. The coefficient of kinetic friction between block and surface is 0.200. The bullet remains embedded in the block, which is observed to slide 0.200 m along the surface before stopping. Required:
a. What was teh initial speed of the bullet?
b. What kind of collision took place between the bullet and the block? Explain your answer comparing the values of the kinetic energy before and after the collision.
c. Calculate the impulse of the block from the moment just after the impact to his final position. Analyze the result.

Which sentences describe disadvantages of burning fossil fuels instead of using hydrogen fuel cells? burning fossil fuels contributes to climate change. burning fossil fuels takes place inside expensive fuel cells. fossil fuels aren't widely available, but pure hydrogen is. fossil fuels are nonrenewable.

Will give brainliest! which statement best describes the difference between strong nuclear forces and weak nuclear forces? weak nuclear forces are involved when certain types of atoms break down. strong nuclear forces are responsible for holding atoms' nucleus together. weak nuclear forces hold bonds between atoms together. strong nuclear forces hold together the nucleus of an atom. strong nuclear bonds prevent atoms from falling apart. weak nuclear bonds prevent compounds from falling apart. strong nuclear forces are involved in breaking electrons from their shells. weak nuclear forces hold protons in the nucleus.

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 2 options: the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the cold balloon expands and rises. the warm balloon shrinks and sinks. the warm balloon expands and rises. the cold balloon shrinks and sinks.